The Glock 17 Gen4 introduces revolutionary design changes to the world's most popular pistol. The modular backstrap design lets the user to adapt the grip to hand size, and the frame surface exhibits the scientifically-designed Gen4 rough textured technology. The dual-recoil spring assembly substantially increases the life of the system, and the enlarged reversible magazine catch easily accommodates left- or right-handed operators. The G17 Gen4 retains the Glock accessory rail for accessory attachment. The Glock Modular Optic System (MOS) simplifies the mounting of popular optics without custom machining of the slide. MOS has four plate options to comply with the specifications of some of the most trusted optic manufacturers in the industry, and a cover plate when no optic is mounted. MOS gives the option of adding tall iron sights, allowing the optic and the iron sights to co-witness. This G17 Gen4 MOS model has a black frame with a black slide, fixed sights, and a 17-round capacity.