This extension is fully machined from 6061 Aluminum and has a hand polished finish it is designed to fit our .380 magazines. It allows the user of the firearm more area to grip the pistol. It does NOT add any additional capacity to the magazine.To install simply replace the floor plate of the magazine assembly with the magazine extension (see exploded view)Specs Weight: 0.20oz. Material: Machined 6061 Aluminum Finish: Hand Polished Aluminum