Sons of Liberty Gun Works NOX, Flash Hider, 223 Remington/556NATO, Nitride Finish, Black, 1/2X28, Fits Dead Air Armament Suppressors and KeyMount Accessories, 9 Ports, Includes Timing Shims NOX9-556 The Sons of Liberty Gun Works NOX series of muzzle devices blend the line between flash hider and compensator. They provide excellent flash suppression" muzzle climb reduction" and allow the quick installation of suppressors and accessories utilizing the Key Mount pattern. Compatible with Dead Air Armaments Sandman line of suppressors. 3 ports on the 3" 9" and 12 O'clock positions to accommodate left and right handed shooters.