The strike industries extended magazine plate for glock 9mm/.40cal was designed to provide smoother magazine reloading through a slow drag/ no snag design while maintaining maximum magazine capacity with any oem glock magazine.The extended magazine plate provides an additional 6 rounds to any 17 glock magazine in addition to adding plus 5 to any glock.40 magazine.Included is strike's special locking plate.-not compatible with 10-round magazinesCaliber: 9mm LugerCapacity: 6Finish: BlackModel: Enhanced Magazine PlateMaterial: PolymerType: Magazine ExtensionModel Fit: Glock 9, 40Brand Fit: GlockCapacity: 6