Reese InterLock hitch balls fit into the stamped Reese Interlock ball mount for a one-wrench-tightening system. Interlock hitch balls will fit all standard ball mounts. When installing Reese TowerPower hitch balls, torque all 3/4-In shank balls to 160 ft. lb. All 1? to 250 ft. lb and 1-1/4? shank balls to 450 ft. lb.