Triple chrome plated, super-fast ball bearing action has been used for years by athletes of all skill levels, trainers and professional gyms to increase speed, build stamina and hone hand-to-eye coordination. All the speed, durability and precision of the traditional pro swivel, only in quick change push-pin security. The industrial ball bearing action allows the speed bag to move in all directions at any time with split-second action. Includes 4 mounting screws.