The GLOCK 35 Gen4 in MOS configuration combines an extended barrel" longer slide dimensions and elongated distance between the sights with the MOS concept" making it easy to mount a reflex sight on the pistol's slide without the need for a new slide or separate mounting system. The Modular back strap system makes it possible to instantly customize its grip to accommodate any hand size. The reversible magazine catch makes it ideal for left and right-handed shooters. Includes three 15-round magazines.