Zero 10X 52V Review

Expert ScoreRead review
38 mph


38 miles


16.5 kg


The Zero 10X 52V was, once upon a time, the go-to performance scooter but sadly this scooter has had its heyday. While it benefits from adjustable suspension, chunky pneumatic tyres, and strong hydraulic brakes, there’re many models that you can get your hands on for the same (or less) money, that outstrip it for specs, features, and build quality. Is the Zero 10X 52V worth the money? Is it right for you? What are the best alternatives? We’ll tackle all these questions and more, bringing you the key things you need to know.


Where to Buy:*

*Offers displayed are from retailers that we trust. If only one offer is available this is because they are the only retailer we recommend. To support our rigorous scooter review and editorial process, we rely on affiliate commissions. These are at no cost to you. Our work is independent and impartial. Read more here.

We are now on Instagram! You'll find...
If you've found value from our reviews and guides we'd really appreciate it if you could follow us – @electricscooterinsider.

Who is it Best For?

Will the Zero 10X Be a Good Fit For You?

The Zero 10X 52V is suitable for both city riding, as well as more challenging off-road circuits. Its adjustable front and rear suspension, 10-inch pneumatic tyres, and giant deck (which also offers plenty of clearance) make the 10X a highly versatile scooter that’ll appeal to a wide range of riders.

Commuters, however, aren’t one of them. At 36.3 kg, the Zero 10X isn’t light, nor is it particularly portable – and why would you want to limit this thing just to weekdays, anyway?

Zero 10X Frame

Ultimately, those who’ll get the most out of the magic the 10X can provide are riders looking for a performance scooter. It’s a fantastic scooter to graduate to from a slower, more commuter-oriented ride before you’re ready to take on the likes of what the VSETT and Kaabo lines have to offer.

Pros and Cons


  • Stylish, durable frame
  • Kickplate and large deck allow for great rider stability and control
  • Beefy 10-inch pneumatic tyres
  • Adjustable dual spring suspension
  • Supports an impressive amount of rider weight
  • Heat sinks repel unwanted heat and protect controllers
  • Key-start ignition inhibits thieves
  • Optional seat attachment


  • No water-resistance rating
  • Battery relies on cheaper Chinese cells, rather than LG or Dynavolt
  • Slightly overpriced when compared to similar models
  • Heavy and lacks portability
  • Some stem wobble

Value for Money

Is the Price Tag Worth it?

The Zero 10X 52V is a great scooter, but do I think it’s worth the price tag? No – there are many models that you can get your hands on for the same (or less) money, that outstrip the 10X for specs, features, and build quality.

Zero 10X on the Beach

To demonstrate what I mean, I’ll let you in on a little secret – the Varla Eagle One is almost identical to the 10X 52V. It’s made by the same manufacturer, sports the same red trim, and has identical dual 1000W motors. Yet, despite all the similarities here, the Varla Eagle One offers so much more. It has an IP54 water-resistance rating and comes with your choice of free gift, as well as protective pads, gloves, inner tubes, and grip tape replacements – things the Zero 10X 52V lacks.

The Varla Eagle One even retails for less than the Zero 10X, and while the free gift sounds gimmicky, you get the choice of things like interchangeable off-road tyres, an extra charger, and more – so it’s not to be sniffed at.

Take a look at the table below to compare the Zero 10X 52V with the Varla Eagle One, and you’ll see that they are pretty much identical twins. I’ve also thrown in the Apollo Pro 52V – it shares the same manufacturer as the Zero and Varla models, so is essentially the third twin – but be mindful that this scooter has been discontinued. For that reason, I won’t be extensively comparing it with the 10X throughout this review. Similarly, the Varla Eagle One is only currently available in the U.S., but the table should give you an idea that the Zero 10X 52V is simply just a rebranded scooter.

SpecsZero 10X 52VVarla Eagle OneApollo Pro 52V
Motors52V 1000W x252V 1000W x252V 1000W x2
Battery18.2Ah Chinese Cells18.2Ah Chinese Cells23Ah LG Cells
Range38 miles40 miles56 miles
Top Speed38 mph40 mph38 mph
Load150 kg150 kg150 kg
Weight36.3 kg34.9 kg34.9 kg
BrakesCable DiscsHydraulic DiscsHydraulic Discs
Tyres10 inch (Air-Filled)10 inch (Air-Filled)10 inch (Air-Filled)
Upgraded ModelsZero 10X 52v + Hydraulic Brakes – also comes with 23Ah battery that has a 60 mile range)None – there is only one version of the Varla Eagle OneNone – there is a downgrade, though, with cable discs instead of hydraulics

For more info about whether the Zero 10X 52V represents good value for your money, explore our performance comparisons further down.

Further Information:

Best Cheap Electric Scooters


What Other Scooters Should You Consider?

VSETT 10+ (25.6Ah)

Why is it Better Than the Zero 10X?

Why is it Worse Than the Zero 10X?


Mantis Pro

Why is it Better Than the Zero 10X?

Why is it Worse Than the Zero 10X?




The handlebars sport a curved ergonomic shape while the large grips are coated in rubber. Combined with the wide 26.7-inch profile, they afford ultimate control of the steering column. However, the trigger throttle brings the comfort level down a factor since your right hand is forced into a claw-like position.

Zero 10X Handlebars

Below the throttle and QS-S4 display, you’ll find the battery voltage meter and key-ignition, and on the left, you have the motor controls. Adorning each side of the handlebars are the brake levers which are well-calibrated but you still need to feather them since the hydraulic discs are fairly powerful and can catch you off-guard if you slam on the brakes.

Zero 10X Handgrip

Unlike its gaggle of younger siblings – including the Zero 9 and the 10 – the 10X handlebars don’t fold. If this is a deal-breaker for you (which it shouldn’t be – folding handlebars on faster scooters like the 10X aren’t the most advisable), keep an eye out as some online stores sell interchangeable pairs of folding handlebars.


The Zero 10X 52V cuts a bulky, brawny figure. The precipitation-hardened structure of its frame is covered in a jet black coat of paint, with splashes of red adorning its swingarms and collar clamp, as well as the trim of its deck and handlebars.

All in all, it’s undeniably a nice-looking scooter – even if it is somewhat lacking in originality.

Zero 10X Frame From Rear

Look closer, and you’ll see it looks the same as the Varla Eagle One (thanks to the manufacturer that they share). While the Eagle One makes some pretty wild design choices – such as its deck grip tape variations, which depict flaming skulls and Apache attack helicopters – the 10X 52V plays it safe, and is unlikely to alienate anyone with the look and feel of its branding.


Wide, long, comfortable, and slathered in a grippy material, the deck is a pleasure to stand on.

Yet what I love most is its kickplate – the raised, angular platform of metal at the scooter’s rear. This is great for placing your back foot on when hitting the 10X’s top speeds since it provides extra traction by striking a more stable stance.

Zero 10X Deck


The wheels are the same kind we see on the Zero 10 – 10 inches in size and pneumatic.

In addition to being terrain-agnostic, they work in cahoots with the front and rear springs to soak up most of the vibrations the road can throw at you. And, thanks to their size profile (i.e. height and width), the 10X remains nimble to ride while maintaining traction with the ground below.

Zero 10X Rear Tire

The combination of the plush, pliable rubber ties and spring suspension system delivers a smooth, comfortable riding experience on urban terrain and affords enough shock absorption to confidently navigate dirt paths and trails. However, where this scooter doesn’t perform well is on rock-strewn terrain, for this, I suggest opting for a scooter that has been designed for off-roading, like the Wolf Warrior or King.

Build Quality & Durability

With a frame made of a tough aluminium alloy and a thick, durable set of parts, the Zero 10X is battle-hardened and ready to ride.

Design-wise, it beefs up on its predecessor – the Zero 10 – with the inclusion of a larger, more durable frame and a strong kickplate.

Zero 10X Durable Frame

The only real issues in terms of build quality are the lack of a formal water-resistance rating, the cheaper Chinese battery cells, and the stem wobble that the scooter’s lacklustre folding clamp can cause.

Fortunately, the irritating stem wobble issue – which, out of the three issues above is the primary one – can be fixed, but it comes at a cost. For £45, you can purchase Zero’s ‘Rugged Folding Clamp’.

This clamp stiffens up the stem to eliminate wobble and I recommend shelling out for it. That said, it’s hard not to have mixed feelings about the way the stem wobble effectively holds you to ransom, essentially forcing you to buy the clamp if you don’t want compromised ride quality.

Weight & Load

The Zero 10X weighs 36.3 kg and is capable of supporting up to 150 kg of rider weight. Load-wise, that puts the 10X’s capacity above the Mantis Pro and VSETT 10+, which – funnily enough – are also the two scooters that most closely parallel the 10X on the metrics of speed and range.

Zero 10X Rear Tire and Frame

A load of 150 kg isn’t to be sniffed at, either – in fact, only two scooters in our 100-strong database outstrip it. One is the EMOVE Cruiser – a model similar to the 10X 52V’s little bro, the Zero 10 – which can support up to 160 kg. The other is the granddaddy of load-bearing – the Wolf King – which can support up to 181 kg, the heaviest load of all the scooters on our books.

Folding & Portability

The 10X doesn’t come stock with folding handlebars, however, the folding stem does lend it a peppering of portability.

Zero 10X Folded

My only gripe about the Zero 10X’s portability is that, when folded, the stem doesn’t lock into place, or fasten to the deck. This makes the scooter difficult to pick up and move around, and – on top of the model’s already hefty 36.3 kg bulk – means I don’t recommend it as a portable solution.


The Zero 10X 52V requires minimal assembly out of the box – you’ll just need to attach the handlebars and tighten up the accessories (QS-S4 display, key-lock ignition, etc) with the included bank of Allen wrenches.

Tip: When fastening the brake levers into place, angle them down. This makes them easier to use while riding.

Zero 10X Handbrake

Ride Quality

Is the Zero 10X Comfortable to Ride?

With the addition of adjustable suspension, the Zero 10X upgrades on the already comfortable ride experience provided by its predecessor, the Zero 10. However, a defining difference is the addition of swingarm suspension that enables the 10X to effectively soak up more harsh terrain as the arms pivot up and down in accordance with the tyre and spring position. In brief, this allows for a greater amount of travel that delivers an overall smoother ride.

On top of that, it retains many of the aspects that made the Zero 10 such an enjoyable ride – such as its optional seat attachment, large comfortable deck, and plush shock absorptive pneumatic tyres.

Zero 10X Rear Suspension

The only disappointing aspect of the 10X’s ride quality is the stem wobble. At best, this is an irritating distraction – at worst, it’s a dangerously egregious design flaw. If you’re set on the 10X 52V, purchasing the aforementioned rugged stem locking mechanism is a must.

Performance & Safety

Speed & Acceleration

The Zero 10X 52V is capable of hitting a top speed of 38 mph, improving on the maximum capacity of its predecessor – the Zero 10 – by a full 7 mph. But how does the Zero 10X’s speed match its closest rivals as far as price and range are concerned? Let’s take a look.

Speed vs Price Comparison

Ranked against the 14 other models in its price class (£1,130 to £1,630), the Zero 10X 52V emerges in second place.

Zero 10X Speed vs Price Comparison (UK)

Topping the chart – which you can dive deeper into below – are the Mantis Pro, Mantis Base, Dualtron Eagle Pro, and Speedway 5, all of which beat the 10X by 2 mph.

Of these top contenders, the Mantis Pro is my top pick. This is as a result of its powerful 60V 1000W dual motors and high-quality LG battery that increase power, torque, and acceleration.

If you can stretch your budget to get the Mantis Pro, I highly recommend doing so – not only does it have superior build quality but it is consistently voted by the electric scooter community as being the best electric scooter.

Speed vs Weight Comparison

When compared alongside the scooters in its weight class of 33.8 to 38.3 kg (with a total of 10 models) the Zero 10X places dead last. This data indicates that the Zero 10X doesn’t offer much pace considering its weight and that its speed-to-weight ratio – which usually follows the rule that the more a scooter weighs, the faster it goes – is a little out of whack.

Zero 10X Speed vs Weight Comparison (UK)

At the opposite end of the rankings, the scooters in the VSETT 10+ lineup share the glory. And it’s hardly surprising – with their huge 60V 1400W motors, dual 35Ah controllers, and ‘Sport’ (a.k.a. ‘Turbo Boost’) mode for injecting 5Ah more power, these scooters outstrip everything similar on the market.

In fact, the VSETT 10+’s top speed is a whopping 32% greater than that offered by the Zero 10X. So, if the adrenaline-pumping thrill of a fast ride is what you seek, I advise upgrading to the VSETT 10+. That said, your bank account may not agree with me – the 10+R will set you back an extra £815. However, the beauty of the VSETT range lies in the fact that you can pick up varying models with different-sized batteries (hence the Ah values). In this case, you can still benefit from the blistering performance of the VSETT 10+ but instead, opt for the less expensive 25.6Ah version that costs £1,995. It’s also worth noting that while the 25.6Ah model has a smaller battery than the 10+R (28Ah), it still delivers a maximum mileage (66 miles) that outstrips the Zero 10X by 74% (equivalent to 28 more miles).


Compared to the other scooters of its ilk, the Zero 10X 52V doesn’t exactly scorch the road when it comes to acceleration. Take a look at how it stacks up in the table below:

Scooter0-15 MPH (Seconds)0-25 MPH (Seconds)
VSETT 10+ 25.6Ah (£1,995)1.73.6
Mantis Pro (£1,500)2.04.1
Zero 10X 52V (£1,380)2.86.2

As you can see, it’s the VSETT 10+ and Mantis Pro hogging the limelight here, courtesy of their 60V motors. However, the 10+ edges the Pro because of its larger motors (1400W vs 1000W), and the fizzing 1.7 seconds it takes to reach 15 mph constitutes one of the fastest acceleration rates in our database of over 100 scooters.

Zero 10X Acceleration Comparison (UK)

But again, the VSETT 10+’s drawback is its price – so, I’d opt for the Pro if your budget is tight.


If you’re careful with it – that is, not pushing the motors up steep hills or caning that thumb throttle – the Zero 10X 52V should be able to hit up to 38 miles off a single charge. But who am I kidding, you’re going to want to run this thing ragged, and based on this riding style you’ll get 23 miles from it.

Just as we did in our speed comparisons above, let’s take a look at how the maximum mileage stacks up against the industry’s most similar scooters.

Mileage vs Price Comparison

Taking the 15 models in the Zero 10X’s price class, the scooter performs below average, falling short of the middle of the rankings. So what’s the best choice here?

Zero 10X Mileage vs Price Comparison (UK)

The logical answer would be the Speedway 5. However, its low-quality Chinese battery tells a different story. While the 75 miles looks impressive on paper, there are better scooters that are more comfortable to ride and that have batteries that will outperform the Speedway 5 where longevity is concerned. For clarity, cheap Chinese battery cells deteriorate faster than higher-quality batteries, like those from LG. Ultimately, this means that the peak performance (75 miles) of the Speedway 5's battery won't last as long as the performance of another scooter that has a higher quality battery.

Next, we have the EMOVE Cruiser, and while this model has a high-quality LG battery, it only has one 1000W motor and is much slower than the Zero 10X. The same goes for the INOKIM Ox with its small 800W motor. As a result, these two aren't good alternatives since they don't belong to the same dual motor performance category as the Zero 10X.

This leaves us with the upgraded Zero 10X with Hydraulic Brake, Dualtron Eagle Pro, and Mantis Pro. Out of these, I would go for the Mantis. Not only is it nicer to ride but it also delivers better build quality since the Zero 10X and Dualtron Eagle Pro both suffer from considerable stem wobble which inhibits the riding experience.

Mileage vs Weight Comparison

Just as it did in our Speed vs Weight rankings, the Zero 10X turns in a miserable showing for mileage, again placing at the bottom of the pile vs the 9 other models in its weight bracket (33.8 to 38.3 kg).

Zero 10X Mileage vs Weight Comparison (UK)

This time, it’s Dualtron scooters that lead the pack, although a quick heads up – if you want a scooter with better build quality, I’d look past both the Ultra and the 3, and pivot instead towards either of the VSETT 10+ scooters. There are primed for long-range rides and have a huge array of features to boot. If you have the funds, it’s worth shelling out the big bucks for the VSETT 10+R. It costs £2,195 but offers almost double the range (74 miles). Food for thought.

Further Information:

Long Range Electric Scooters

Hill Climbing

The Zero 10X 52V can tackle hills of up to a 30-degree incline rate, which means it can handle most urban slopes comfortably.

However, if you want to zip up hills faster, and take on more challenging gradients, I’d recommend the VSETT 10+ (25.6Ah). It has a mouth-watering incline rate of 35-degrees, so can easily cope with anything you can throw at it.

Shock Absorption / Suspension

The 10X is fitted with dual spring suspension, which – on top of its 10-inch pneumatic tyres – helps to soak up most of the vibrations you’d otherwise feel on rough terrain.

Zero 10X Spring Suspension

Plus, the 10X 52V’s front and rear shocks – in addition to being seriously robust – are adjustable. While the mechanism here doesn’t have a patch on something like the NAMI Burn-e, where you can dial in the exact amount of damping, it still comes in handy when you need to tighten or loosen the strength of your scooter’s shock absorption to fit different types of terrain.

The swingarms play a key role in the scooter’s ability to react to the compression and rebounding of the springs, too. They essentially ensure that you aren’t bouncing up and down but instead keep you planted to the deck as they pivot up and down in relation to the movement of the springs.


While the 38 mph top speed isn’t quite as fast as many similar scooters on the market, it’s still certainly not slow – and to control your speed the 10X comes with dual disc brakes.

Zero 10X Disc Brake

Together, these brakes allow the 10X to come to a stop in 4.9 meters from a speed of 15 mph. Generally, I consider a good braking distance to be between 3 and 3.4 meters – so the 10X does fall short here.

For reference, the upgraded version of the Zero 10X that comes with hydraulic brakes comes to a stop in 3.7 meters.

Zero 10X Zoom Hydraulic Brake Caliper

This is also born out in our analysis of similar scooters. Several models in the Zero 10X’s pricing bracket – including the Mantis Pro, Mantis Base, and Mantis 8 Pro – all have hydraulic braking setups. These hydraulic brakes help this group of 10X competitors to outstrip it when it comes to braking performance. For instance, the Mantis Pro can come to a stop in just 3 meters, while the Base and 8 Pro take 3.4.

Similarly, the VSETT 10+ (25.6Ah) delivers superior stopping power to the 10X, coming to a halt in 3 meters.

Charge Time

The battery takes around 10 to 12 hours to reach full charge.

However, purchasing an extra 52V charger – which you can do for just £65 – will cut this time in half, meaning you can get back on the road quicker.

Extra Features

QS-S4 Throttle Display for Customized Performance Configuration

The QS-S4 display – which is located just to the right of the handlebars – doubles as both a finger throttle and screen. That means it’s not only your go-to for regulating your scooter’s speed and acceleration, but also for quick-look insights into your ride time, distance travelled (current trip, and all-time), battery life, riding mode, and current speed.

Cooler still, this device has a clandestine USB port tucked away just behind the screen. You can use this to charge your accessories if you’re desperate, but I wouldn’t endorse it – current-craving iPhones and GoPros won’t just drain your 10X’s battery, but potentially cook its circuits, too.

Zero 10X Handlebar and QS-S4 Display

Dig deeper into what the QS-S4 device is capable of and you’ll come across its P-settings. These provide you with a range of customizable functions, including:

  • The strength of your scooter’s regenerative braking system and acceleration
  • The brightness of its display
  • Auto turn-off settings
  • Cruise control

The QS-S4 isn’t the most customizable display on the market, but it's reliable, user-friendly, and popular enough to feature on scooters from the esteemed Kaabo, Apollo, VSETT, and Varla brands – so it’s worth getting the hang of to take advantage of its capabilities.

Motor & Turbo Control Buttons

To the left-hand side of the handlebars is a pair of buttons.

The one marked Eco/Turbo refers to your riding mode, and allows you to toggle between the two. Staying in ‘Eco’ will help conserve your battery and access the 10X’s maximum range but at the expense of your pace and acceleration. Ramping things up to ‘Turbo’ mode will do the opposite – you’ll forgo your chances of a longer ride, but benefit from increased torque.

Similarly, the button reading ‘Single/Dual’ controls whether you’re riding with both motors engaged, or just one. Riding with dual motors will help you get the most power out of the 10X but at the expense of battery life.

Battery Voltage Display

The Zero 10X 52V comes with a battery voltage display. This is situated just west of the scooter’s QS-S4 screen, on the right side of the handlebars.

This voltage display appears in the form of a number that you can use to decode your scooter’s remaining battery life. We’ve put together a rough guide that you can use to understand how much juice you have left in the tank:

Battery PercentageVoltmeter Reading

Your QS-S4 will also provide a basic battery bar visualization of your remaining battery life. Using the voltmeter is preferable, though, because of how granular the level of detail is. This allows for a more accurate estimation of the amount of ride time you have remaining.

Cruise Control

The built-in cruise control feature is accessible via the QS-S4’s P-settings. Simply navigate to setting P6 on the screen to activate it, and – when you’re out on the road and have reached the set cruising speed – it’ll engage automatically. This allows you to relax your grip on the throttle and take it easy.

When you’re done, gently squeeze the brakes to regain manual control over your speed.

Adjustable Suspension

As mentioned earlier, the spring suspension is adjustable, meaning you can customize it to fit the profile of a range of different riding surfaces.

The process is a little technical – and will take some getting used to the first couple of times you do it – but ultimately, it’s relatively quick and headache-free.

You do need to have your c-spanner at the ready, though.

LED Lights

Compared to the sensational mood deck lighting of the Zero 10, the 10X’s LED display keeps it surprisingly muted and subtle. The scooter relies solely on deck-embedded button lights at the front and rear. Predictably, their poor placement and lack of brightness mean that, while perfectly adequate for getting you spotted by other vehicles on the road, they aren’t sufficient to provide you with good visibility for riding at night.

Zero 10X Rear Button Lights

If you are planning on taking to the streets after dark, you’ll need to invest in an extra attachable light – ideally, one that’s bright enough to serve as a headlight. Strap this high up on the stem or handlebars for the best results.

Key-Start Ignition (Anti-Theft Function)

Just as cars have ignitions to stop random people hopping in and taking them for a spin, so too does the Zero 10X.

Essentially, this means the scooter will be immobilized – that is, prevented from turning on – unless you unlock it with your key. Helpfully, this will allow you to leave it alone for short periods – say, popping into the local grocery store for a carton of milk – and not have to worry about someone riding off on it. Sure, it could still be rolled away without the key – but at 36.3 kg, I don’t envision that being a particularly quick process.

Heat Sinks to Expel Unwanted Heat and Protect Controllers

Controlling the impressive nominal total power output of 2000W from the dual hub motors is a pair of 25Ah speed controllers. As you can imagine, with all that power and kinetic energy fizzing around, these controllers tend to get pretty hot.

Fortunately, the controllers are protected with heat sinks. These devices pull cool air in and across all the vital components to regulate the temperature of the controllers and motors. This is essential for the longevity of the scooter.

Optional Seat Attachment

For £95.99 you can purchase a seat attachment. It’s comfortable, fully adjustable, and comes with in-built hydraulic suspension – so it’s ideal for longer journeys.

Zero 10 Detachable Seat

The seat is super easy to install, too – there are a few screws you’ll have to tighten, but no drilling or technical stuff is required.

Specification: Zero 10X 52V Review



Suitable For



Off-Road, Urban


Folding Frame

Weight (kg)


Rider Weight (kg)


Tyre Size (inches)


Tyre Type

Pneumatic (Air-Filled)

Speed (mph)


Range (miles)


Max Incline (%)


Charge Time (hours)



Front & Rear


Disc, Hydraulic

Extra Features
Extra Features

Cruise Control, Detachable Seat, LED Display, LED Lights

Specification: Zero 10X 52V Review



Suitable For



Off-Road, Urban


Folding Frame

Weight (kg)


Rider Weight (kg)


Tyre Size (inches)


Tyre Type

Pneumatic (Air-Filled)

Speed (mph)


Range (miles)


Max Incline (%)


Charge Time (hours)



Front & Rear


Disc, Hydraulic

Extra Features
Extra Features

Cruise Control, Detachable Seat, LED Display, LED Lights

Zero 10X 52V Review
Zero 10X 52V Review


How We Conduct & Support Our Electric Scooter Research:

To support our rigorous scooter review and editorial process, we rely on affiliate commissions. These are at no cost to you.


If you read our guides and reviews, find a scooter that you like, and click through to the retailer then we may earn a commission. We only earn a commission if you purchase a scooter and are happy with it. If you decide that you don’t like it and return it, we don’t earn a commission.


Our work is independent and impartial. Retailers and manufacturers do not influence our reviews. This is extremely important to us as our mission is to help you find your perfect scooter.


Read more about our four core values, the scooter review process, editorial policy, and how Electric Scooter Insider is supported.

Electric Scooter Insider