LanTac USA LLC Dragon, Muzzle Brake, 223REM/556NATO, Black Color, With Dead Air Sandman KEYMO Suppressor Mount, Includes Timing Shim DGN556B-DA Manufactured to the highest quality standards and featuring a patented design" the LANTAC DGN762B-DA Muzzle Brake offers improved recoil management and muzzle rise over competitors' products. Its unique Short Energy Pulse system reduces length of recoil so that repeating shot energy cannot overlap and knock the shooter off target. Full auto fire is possible with massively reduced recoil and muzzle climb" meaning that all shots fall on target. For the first time shooters can now enjoy advanced weapon control with the ability to mount the entire range of Dead Air Sandman KEYMO silencers to their firearms. The mount design is fully licensed from Dead Air" therefore customer's suppressor warranty remains unaffected. Ships with timing shim set. Lantac recommends the use of semi-permanent thread locker Rocksett" sold separately.