Recommended for use on carpet and tracks with high traction, the car rotates better and drives better through corners. Fits both XB4 & XB4 2WD. Aluminum rear lower suspension holders with Integrated Suspension Settings (I.S.S.) allows for quick & easy suspension geometry setting. This XRAY concept was first introduced in the very first XB8 and now has been carried over to the 1/10 scale XB4. Using eccentric suspension bushings inserted into aluminum suspension blocks, along with additional suspension shims, the XB4 suspension geometry can be completely adjusted.