This is a factory Glock (17, 19, 22, 23, 26, 27, 31, 32, 33, 37) +2 magazine extension with the magazine insert. It will allow all 9mm models to hold 2 extra rounds and allow any 40 s&w, .357 sig, .45 gap models to hold 1 extra round.
WILL NOT FIT .45 ACP OR 10MM MODELS
