Kawasaki Strong The newest edition to the MULE™ family, the MULE PRO-DX™ side by side, is our powerful, most capable diesel MULE side x side ever. Built on the same rugged platform as the MULE PRO-FX™, this innovative side x side comes equipped with the largest cargo bed in class all while offering comfortable full-size three-passenger seating. To top it off, the MULE PRO-DX is backed confidently by the Kawasaki STRONG 3-Year Limited Warranty.