Centennial Defense Systems Extended Mag Release for Gen 4-5 9mm .40S&W .357SIG Glock Stippled Burnt Bronze. It is designed to fit in most holsters and will fit Gen 4-5 Glock models in 9mm .40 S&W .357 Sig as well as Gen 4 10mm and .45ACP models. Note: Will NOT fit G42 G43 or Gen 1-3 pistols. Specifications for Centennial Defense Systems Extended Mag Release for Gen 4-5: Manufacturer: Centennial Defense Systems Gun Make: Glock Fabric/Material: 6061 Aluminum Package Contents: Centennial Defense Systems Extended Mag Release for Gen 4-5 What firearm models does the manufacturer say Centennial Defense Systems Extended Mag Release for Gen 4-5 is compatible with? The manufacturer says that Centennial Defense Systems Extended Mag Release for Gen 4-5 is compatible with Glock 23 Glock 25 Glock 35 Glock 34 Glock 24 Glock 22 Glock 17 Glock 33 Glock 27 Glock 26 Glock 32 Glock 31 Glock 19 Glock 20 Glock 29 Glock 30 Glock 21 Glock 40 Glock 41Centennial Defense Systems 20426: Extended Mag Release for Gen 4-5 9mm .40S&W .357SIG Glock Stippled Burnt Bronze