Specially designed flash hider that is compatible with the patent pending Yankee Hill fast-attach sound suppressor while retaining the excellent signature reducing properties of the original Phantom flash suppressor. Yankee Hill Machine Muzzle Brake Phantom 5.56 Quick Detach Mount 1/2-Inch-28 Thread AR-15 Steel Parkerized. Specially designed flash hider that is compatible with the patent pending Yankee Hill fast-attach sound suppressor while retaining the excellent signature reducing properties of the original Phantom flash suppressor. 1/2-Inch-28 RH Thread. Compatible with YHM 5.56 and 7.62 Sound Suppressors.