This is an optional Team Losi Racing Complete Ball Differential with Tungsten Balls. This ball diff is a direct replacement for the entire 22 family of vehicles. The Team Losi Racing Tungsten Ball Diff is a great way to upgrade a RTR kit with a smooth, high performance, race proven diff that will provide immediate results that will show up in your lap times. Tungsten diff balls will create smoother differential action and increase the life span of the diff, keeping you on the track longer. This can also be beneficial for racers to have on hand as a spare part, allowing quick diff replacement, rather than needing to rebuild the existing diff. Includes all the parts needed to build one differential, as well as one tube of diff grease, and one tube of black grease. Features: Compatible with all 22 series vehicles Great upgrade for 22 RTR vehicles Tungsten Carbide Diff and Thrust Balls provides a smoother diff and longer life All parts included to build a complete diff Improve lap times