Polymer vertical grip that mounts onto most weaver, Picatinny, and Mil-Spec 1913 rails.Tool-less design for mounting on rails. Twist bottom knurled knob until recoil detent is flush below rail mount. Slide vertical grip onto rail. Use side witness holes to align with a rail cross slot and tighten knurled knob until detent locks grip to the rail.Grooved vertical grip surface for a secure grip.3.75H Grip surface Overall height 4.5HVertical grip is made from black polymer plastic.Vertical Grip Not designed for Pump Shotguns