G36 Flash Hider, 5/8-24 thread pitch, Shoulder Mount, KeyMount In order to use this device with a suppressor, it must be installed by a professional - to ensure it is properly mounted and aligned. Do NOT shoot without checking alignment with bore rods. JMac Customs is not responsible for any damage to the suppressor, or any injury resulting from improper installation. Some firearms are NOT suitable suppressor hosts, just because you can thread this muzzle device on, does NOT mean it is safe to use. The GFHC is a combination of the German G36 flash hider and DeadAir Silencers KeyMount Non-Compensated version that does NOT have to be timed SHIMS ONLY NEEDED FOR TIMING Mfg: Jmac Customs