The Armaspec TCB-31 Tactical Combat Button is an extended mag release designed to improve the functionality and ergonomics of the factory button. The TCB increases the size of your factory button by 263% making it easier and faster to perform magazine changes. The size and ergonomic design enables button engagement without changing your grip position. FeaturesFaster magazine change263% larger than Mil-Spec mag release buttonCompatible with Mil-Spec AR-15 lower receiversErgonomic design