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