The Modular Back Strap design lets you instantly customize its grip to adapt to an individual shooter's hand size. The surface of the frame employs the new scientifically designed, real-world-tested, Gen4 rough textured technology. Internally, the new GLOCK dual recoil spring assembly substantially increases the life of the system. A reversible magazine catch, changeable in seconds, accommodates left or right-handed operators. The G23 Gen4 in .40 caliber retains the GLOCK accessory rail for your attachments.