PX4 Magazine Extension Kit
Beretta PX4 Storm Magazine Pad Extension and Spring. Expand your magazine capacity with this, easy-to-replace part from Beretta. Convert your factory PX4 9mm 17 round magazine to hold 20 rounds or your 14 round .40 S&W magazine to 17 rounds. Simply replace your magazine floorplate and spring with this kit and use your existing magazine body and follower.