Made from all steel cogs for durability and 5:1 gearing for pulling power. with taylor-made type 380 motor with ball bearing shaft housing for stronger torque and smoother rotation. Come with 3 different sized gear pinions for motor shaft for light, medium or heavy tank performance profile. Compatible with and can be adapted for most Heng Long, Taigen, Torro and Matorro 1/16 scale radio controlled tanks. This kit is intended for Heng Long 3818 Tiger 1 & 3848/3849 Panzer III Plastic Chassis (minor modification required). Some assembly required. All tools and Instructions in English are included. Supplied as a pair for one tank.