Features and Specifications:Manufacturer Number: UZI-A1ProMag UZI .45 ACP Magazine 22 Rounds Blued SteelCaliber: .45 ACPCapacity: 22 RoundsBody Material: Heat Treated SteelSpring Material: Heat Treated Chrome-silicon WireFollower Material: PolymerFollower Color: BlackDuPont Zytel Polymer Follower, Lock Plate, and Base PlateFinish: BluedFits:.45 UZI Carbines