Glock 17 factory 17 round Generation 5 magazine, designed for Glock 17/34 but fits all Glock 9mm pistols (Glock 19 and Glock 26 as an extend magazine). Check out the XGrip Adapter if you want to use them as an extend magazine. The XGrip adapter will fill the space making a grip instead of just having the magazine stick out. This factory Glock magazine will fit the following models: G17, G34, G19 & G26 They have a stiff metal tube encased in the proven Glock high-tech polymer. This resists deformation – even when dropped from great height or exposed to extreme environment conditions.