Anyone who loves powerful toy trucks and building toys will enjoy building the LEGO Technic 4x4 Mercedes-Benz Zetros Trial Truck (42129) model. This truck features realistic details and offers an enjoyable building experience for adults and children aged 12 and up. Open the cab doors and hood, see the working suspension on all four wheels, and open the service hatch to inspect the gearbox. The model also features a detailed engine with a rotating cooling fan. For the first time in LEGO Technic, this model features a differential lock. Use the app to lock and unlock the differential gears to steer the truck off-road. Explore the App With this model, building is just the beginning. Use the CONTROL+ app to test this powerful machine. Use the different control screens to steer and operate the differential lock. With in-app challenges and achievements, there are many ways to play. Building toy enthusiasts will love building their own Mercedes-Benz Zetros trial truck model. Explore all its cool functions with the LEGO® Technic™ CONTROL+ app. The LEGO® Technic™ 4x4 Mercedes-Benz Zetros Trial Truck model (42129) features intricate and realistic details, such as working suspension on all four wheels, a detailed gearbox, and a differential lock system. Realistic design features include race car-inspired stickers and two fire extinguishers. Use the flags to create an obstacle course and test the truck's capabilities on different terrains. This set is perfect for adults and children aged 12 and up to enjoy together. It's also a great toy for young LEGO® builders looking for a challenging building experience. The truck model measures over 8" (21 cm) high, 19" (48 cm) long, and 7" (19 cm) wide. Requires 6 AA batteries (not included). The battery box can be easily detached, making it simple to change batteries when needed. This app-controlled LEGO® Technic™ truck is powered by one smart hub with Bluetooth® technology, three large motors, and one medium motor, all included in the set. Condition: Used, very clean Box and instruction manual are included.