The USBC Equipment and Specification team's process for testing and approving removable bowling ball devices ensures that no movable parts exist inside a bowling ball, including the weight block, thumb insert, and finger grips. This ensures the safety of bowlers, protects the bowling establishment from potential damage, and preserves the integrity of the game. Click here for a list of approved removable bowling ball devices. For further information, please consult the Equipment and Specifications Manual.