Traxxas Deep-Terrain Traxx - TRX-4 (4) (complete set)

Traxxas Deep-Terrain Traxx, TRX-4 (4) (complete set, front & rear) 

CAUTION: USE LOW GEAR Drive with the transmission in low gear to prevent overheating and permanent motor damage. On models equipped with single-speed transmissions, the stock gearing (17-T pinion and 39-T spur gear) is suitable for general use in most terrain with NiMH or 2s LiPo batteries. For mud or snow use, or when using a 3s LiPo battery, you must replace the stock gearing with an 11-T pinion and 45-T spur gear prior to driving.