This is a bearing kit by Avid RC for all versions of the Xray XB2 Dirt Edition. This version includes a differential and a 3 gear transmission where the Carpet Edition has a gear diff and a laydown 4 gear transmission. If you are going to run the optional 4 gear stand-up transmission in the dirt version you will need to purchase (2) 3x8x4 bearings for the extra idler gear.
XB2 Dirt Edition