Modular optic system simplifies sight mounting Modular backstrap design for a custom grip Gen4 rough, textured technology Dual recoil spring assembly The M.O.S. modular optic system of these Glock Centerfire Pistols allows you to easily mount popular optic sights without the need for costly custom machining. This means faster target acquisition, faster target transition and improved accuracy at both short and long range, making these pistols ideal for competitive shooting, target shooting and concealed carry. Polymer grips feature the modular backstrap design, which allows for easily interchanging backstraps, creating a custom grip to fit any hand size. Polymer frame sports Gen4 rough, textured technology to provide a phenomenal grip. Dual-recoil spring assembly lessens recoil and increases the pistol's durability. Includes a cover plate for when no optic is mounted as well as four plate options to comply with the specifications of most optics. Note: Optic not included.