Active Differential set for XB2. The unique XRAY Active Differential is a high-performance, adjustable front gear differential for XB2 . . . vastly enhancing the buggy's rate and handling characteristics. The unique design for the internal elements making use of various angled sections enables the diff gears to engage on-power to boost the forward traction, making it quicker and easier to drive. Even though the XRAY Active Differential is a performance selection for serious racers who want to gain an advantage on superior speed and handling, it's also of good benefit to drivers of all amounts that are looking an even more predictable and easy-to-drive car in every race conditions. Ball-bearings maybe not included Fits: XB2, XT2