This Beretta PX4 magazine is a standard factory replacement magazine with an extended base plate to give you a better grip and more capacity. It's designed the full size PX4 models chambered in 9mm Luger. The magazine is capable of holding up to 20 rounds of ammunition. It's constructed with the standard 17 round steel tube and features a +3 round extended polymer base plate. Made to Beretta's specifications and tolerances, using the same manufacturing and materials as the original equipment magazines. Note: This magazine will fit the Compact and Sub-Compact Models however it will extend from the grip.