The Forward Controls Design 6310KM is designed for use with the Dead Air Keymo mounting system. The 6310KM is threaded for 5/8x24, precision machined from solid 4140 steel bar stock, heat treated and QPQ treated. Its 3 and 9 o'clock ports are 25% smaller (shorter and narrower) than the other three upward facing ports so more gas is vented through the upward facing ports. The 6310KM is a light and short blended performance muzzle device. It provides 20 to 25% better muzzle rise compensation than the A2. Forward Controls Design is an authorized licensee of Dead Air suppressor mounts. 6310KM has wrench flats for torquing it on the barrel. Do not use a screw driver and insert it into one of its ports to torque it