Glock Buffer Fits: 17, 17L, 18, 19,20, 21, 22, 23, 24, 24C, 31, 32, & 37. Does not fit Gen 4 Glocks or subcompacts. This buffer eliminates the metal slide from contacting the polymer frame. Fits between the Recoil spring and Slide. Reduces felt recoil for an enhanced muzzle contol and a longer service life.