The optional Catappi tracks for the Mini-Z 4x4 offer exceptional traction across a full range of off-road terrain. It seems mostly unstoppable but ever now and then, you many need to repair the tread after considerable use and abuse. Kyosho offers the MXW009-1, which features enough new tread blocks to re-shoe an entire track. So, if you're in need of repairing all your tracks, four packs of Catappi tracks will re-shoe an entire set of tracks.