Anyone who loves powerful toy trucks and construction toys will have lots of fun building this LEGO Technic App-Controlled 4x4 Mercedes-Benz Zetros Trial Truck (42129) model. Packed with realistic features, this truck toy offers an engaging build for adults and kids aged 12 and up. Open the cab doors and hood. The model also features a detailed engine with spinning radiator fan. In a first for LEGO Technic, this model has differential locking. Lock and unlock the differentials using the app to maneuver the truck over rough terrain. Explore the app With this model, the build is just the start. Use the CONTROL+ app to put this mighty machine to the test. Use the different control screens to steer and operate the differential locking. With challenges and achievements in the app, there are so many ways to play.- The toy truck model measures over 8 in. (21 cm) high, 19 in. (48 cm) long and 7 in. (19 cm) wide.- Requires 6 x AA batteries (not included).