Recommended for usage on carpeting and tracks with a high traction, the car rotates better and drives better through corners. Fits both XB4 & XB4 2WD. Aluminum backside lower suspension holders with Integrated Suspension Settings (I.S.S.) allows for quick & easy suspension system geometry setting. This XRAY concept was first introduced in the very first XB8 and today was carried over to the 1/10 scale XB4. Using eccentric suspension bushings placed into aluminum suspension obstructs, along with additional suspension shims, the XB4 suspension system geometry is entirely modified.