Product Details
The Losi® Lasernut U4 1/10-scale 4WD Rock Racer (RR) RTR with Spektrum™ Smart builds on the TEN platform delivering a great out-of-the-box experience to be able to throw down in any 2.2 Unlimited class.
Key Features
- TEN 4WD Platform
- Spektrum™ Firma™ 130A Brushless Smart ESC and Firma 4-Pole 1900kv 550 Motor
- Spektrum DX3™ 2.4GHz radio system with AVC® and optional telemetry
- Officially-licensed Lasernut Racing Scale Body & Cage
- RTR Completion Level is fully assembled and only requires an IC5/EC5 LiPo battery and compatible charger for operation
In The Box
- (1) Lasernut U4 4WD Brushless RTR Vehicle
- (1) Spektrum™ Firma 130A Brushless SMART ESC (installed)
- (1) Spektrum™ SR6100AT Receiver with AVC
- (1) Spektrum DX3™ 2.4GHz Radio Transitter
- (1) Product Manual
- (1) Spektrum Firma 4-Pole 1900Kv 550 Motor (installed)
Needed to Complete
- (1) 3S-4S LiPo Battery with EC5™ or IC5™ connector
- (1) Compatible Battery Charger
- (4) AA batteries for Transmitter
Features
Product Specifications
| Completion Level | Ready-To-Run |
| Drivetrain | 4WD |
| Drive Type | Forward/Brake/Reverse |
| Make | ARMADA |
| Product Height | 8″ (203 mm) |
| Ball Bearings | Full set |
| Chassis | 0.12″ (3mm) thick 6061 T-6 aluminum |
| Product Weight | Varies with equipment |
| Vehicle Type | Rock Racer |
| Water-Resistant | Yes |
| Battery | Sold Separately |
| Approximate Assembly Time | No assembly required |
| Body | Trimmed and painted |
| Brakes | Integral with ESC |
| Pinion | 12T |
| Scale | 1/10 |
| Bushing Material | Metal |
| Charger | Sold Separately |
| Differential | Sealed viscous filled |
| Max Battery Dimensions | 5.45 x 1.83 x 1.38″ (138.5 x 46.5 x 35mm) |
| Receiver | Included |
| Shock Type | Oil-filled aluminum body |
| Power Type | Electric |
| Gear Pitch | MOD1 |
| Servos | Included |
| Final Drive Ratio | 12.97:1 |
| Motor Type | Brushless |
| Rear Track | 13.25″ (336mm) |
| Speed Control | Included |
| Wheelbase | 14.75″ (375mm) |
| Ground Clearance | 1.75″ (44mm) |
| Front Track | 13.25″ (336mm) |
| Vehicle Size | Standard |
| Product Width | 13.25″ (337 mm) |
| Radio | Included |
| Technology | AVC and SMART |
| Internal Gear Ratio | 3.89:1 |
| Product Length | 24.3″ (617 mm) |
| Suspension | Independent |
| Track Surface | 13.25″ (336mm) |
| Spur Gear | 40T |



























































John Smith –
The Losi Lasernut U4 is an absolute beast on the trails! The brushless motor and 4WD system make it unstoppable. AVC works like a charm to keep it stable at high speeds. Highly recommend!
Emily Johnson –
This rock racer is a blast to drive! The blue color looks fantastic, and the Smart feature makes setup a breeze. However, the battery life could be a bit longer.
Michael Brown –
I’m impressed with the build quality and performance of the Lasernut U4. It handles rough terrain with ease, and the AVC system is a game-changer. Worth every penny!
Sarah Davis –
Great product overall, but I had some issues with the remote control connectivity. Once resolved, it’s been a joy to drive. The brushless motor is incredibly powerful.
David Wilson –
The Losi Lasernut U4 is perfect for both beginners and experienced RC enthusiasts. The RTR setup is convenient, and the performance on rocky terrain is outstanding.
Laura Martinez –
I love how responsive and agile this rock racer is. The AVC system really helps maintain control, especially on uneven surfaces. The blue color is a nice touch too!
James Anderson –
This is a solid RC car with great features. The brushless motor provides plenty of power, and the 4WD system handles all types of terrain. A bit pricey, but worth it.
Jessica Taylor –
The Lasernut U4 is a fantastic rock racer. The Smart feature makes it easy to get started, and the AVC system ensures smooth handling. Highly recommend for RC enthusiasts!
Daniel Thomas –
This RC car is a lot of fun to drive, but I wish it came with a better battery. The brushless motor and 4WD system are top-notch, though. Great for off-road adventures!
John Carter –
The Losi 1/10 Lasernut U4 4WD Rock Racer is an absolute beast on the trails! The brushless motor provides incredible speed and power, while the Smart and AVC technology ensures smooth handling even on rough terrain. The blue color looks fantastic, and the RTR setup made it easy to get started right out of the box. Highly recommend for anyone looking for a high-performance rock racer!
Emily Davis –
I’ve been using the Losi Lasernut U4 for a few weeks now, and it’s been a blast! The 4WD system handles rocks and uneven surfaces with ease, and the brushless motor is both powerful and efficient. The AVC feature is a game-changer, especially for beginners like me. The only downside is the battery life, which could be a bit longer. Overall, a fantastic product!
Michael Thompson –
This rock racer is built like a tank! The Losi Lasernut U4 has exceeded my expectations in terms of durability and performance. The Smart technology is a nice touch, allowing for easy tuning and customization. The blue finish is sleek and eye-catching. It’s a bit pricey, but definitely worth the investment for serious RC enthusiasts.
Sarah Johnson –
The Losi Lasernut U4 is a joy to drive! The 4WD and brushless motor combo makes it a powerhouse on any terrain. I love the AVC feature, which helps keep the car stable during high-speed runs. The RTR setup was a breeze, and the blue color is stunning. My only complaint is that the tires could be a bit more durable. Still, a top-notch product!
David Martinez –
This is hands down one of the best rock racers I’ve ever owned. The Losi Lasernut U4 is fast, durable, and packed with features like Smart and AVC technology. The blue color is a nice touch, and the RTR setup made it easy to get started. It’s a bit on the expensive side, but the performance and quality justify the price. Highly recommend!