Remarkable for its accuracy and light recoil the Glock 21 Gen 4 delivers the legendary stopping power of the 45 ACP round with a higher magazine capacity. The modular back strap design on the G21 Gen 4 lets you instantly customize the grip to adapt to an individual shooter’s hand size. Its frame employs the scientifically designed real-world-tested Gen 4 rough textured technology. Internally the Glock dual recoil spring assembly substantially increases the life of the system. A reversible enlarged magazine catch changeable in seconds accommodates left or right-handed operators.