Maximum Force adapters are intended for factory dually trucks that want to run the larger semi style wheels. 19.5″ 22.5″ or 24.5″. The wheels must have a 10 bolt on 285.75mm bolt circle pattern. The kit consists of the 4 adaptors ( 2 front, 2 rear ) and all mounting hardware. These are 8 lug to 10 lug hub-centric all steel adaptersideal for the abuse and loads required by 1 ton and 3/4 ton truck/SUV applications. . Mount 10 lug semi wheels on your truck. MADE IN AMERICA!