One Aluminum Center Gear Box

Offset from stock wheel hex: +6mm/side

but it's more powerful and more efficient to handle bigger motors and higher capacity battery packs for increased speeds and fun

Spring Length: 66mm

and wheel-spinning

Hitec RCD - HPP-21 PC Programmer, for Hitec Digital Servos Electric Accessories One Aluminum Center Gear BoxThe HPP 21 Digital Programmer and servo tester allows you to access all the programable features right from your PC. Features: PC Programmer for Hitec Digital Servos PC Based Digital Servo Programmer and Tester Programs all Hitec Digital Servo Parameters Tests all Brands of Servos Free Downloadable Software USB PC Connection