The 4D system is a new layout of beyblades where the fusion wheel is split is into 3 pieces and the performance tip and the spin track are combined. This increases the parts of a beyblade to 6 pieces instead of five. Not all beyblade have both a combination of a 4D fusion wheel and a 4D bottom(ex: Fang Leone 130W2D).

180px-MFB 4DParts

4D System