Centennial Defense Systems Extended Mag Release for Gen 1-3 9mm .40S&W .357SIG Glock Stippled Black. It is designed to fit in most holsters and will fit Gen 1-3 Glock models in 9mm .40 S&W .357 Sig 10mm and .45ACP. Note: Will not fit G42G43 or Gen 4/5. Specifications for Centennial Defense Systems Extended Mag Release for Gen 1-3: Manufacturer: Centennial Defense Systems Gun Make: Glock Gun Model: Glock 27 Glock 26 Glock 32 Glock 31 Glock 23 Glock 20 Glock 19 Glock 33 Glock 29 Glock 25 Glock 30S Glock 20SF Glock 35 Glock 21SF Glock 24 Glock 34 Glock 22 Glock 17 Glock 21 Glock 30 Fabric/Material: 6061 Aluminum Condition: New Package Contents: Centennial Defense Systems Extended Mag Release for Gen 1-3 What firearm models does the manufacturer say Centennial Defense Systems Extended Mag Release for Gen 1-3 is compatible with? The manufacturer says that Centennial Defense Systems Extended Mag Release for Gen 1-3 is compatible with Glock 21 Glock 25 Glock 20SF Glock 30S Glock 21SF Glock 35 Glock 34 Glock 24 Glock 22 Glock 17 Glock 19 Glock 30 Glock 29 Glock 33 Glock 27 Glock 26 Glock 32 Glock 31 Glock 23 Glock 20Centennial Defense Systems 20364: Extended Mag Release for Gen 1-3 9mm .40S&W .357SIG Glock Stippled Black