The Modular Back Strap design of the GLOCK 17 Gen4 allows one to easily customize its grip to add comfort" regardless of the shooter's hand size. The surface of the frame features the new Gen4 rough textured profile. Internally" the new GLOCK dual recoil spring assembly substantially reduces the wear and tear on the system. A reversible enlarged magazine catch" changeable at user level accommodates left and right-handed operators.