Front/Rear Active Differential set for XB4. The initial XRAY Active Differential is a superior, adjustable front side gear differential for XB4 ... greatly improving the buggy's rate and managing characteristics. The special design of the internal components utilizing various angled segments permits the diff gears to interact on-power to improve the forward traction, rendering it faster and better to drive. Although the XRAY Active Differential is a performance option for serious racers who wish to gain an advantage on superior rate and management, it is also of good advantage to drivers of most amounts looking a far more predictable and easy-to-drive vehicle in most racing conditions. Ball-bearings perhaps not included Fits XB4'20-21
