The Beretta APX striker-fired semiautomatic pistol, utilizing a removable internal metal chassis, can be easily modified with replaceable grip frame housing and is simple to disassemble and maintain. The extremely low profile, snag-free, design of the APX makes it easy to carry and draw from the holster. To accommodate right or left-handed use, the magazine release button can be easily reversed while the hold-open lever is present on both sides of the gun. Furthermore, to enhance the pistol ergonomics, the APX is fitted with quickly interchangeable backstraps of different thicknesses to accommodate most users’ grip.