Recommended for usage on carpeting and songs with a high traction, the vehicle rotates better and drives better through corners. Fits both XB4 & XB4 2WD. Aluminum back lower suspension holders with incorporated Suspension Settings (I.S.S.) permits fast & easy suspension geometry environment. This XRAY concept was initially introduced within the very first XB8 and now is carried to the 1/10 scale XB4. Using eccentric suspension bushings inserted into aluminum suspension obstructs, along with additional suspension shims, the XB4 suspension geometry may be totally adjusted.