Rearden MFG FHD HT Flash Hider 13x1 LH HT Heat Treat. This is an updated version that has larger wrench flats on the rear. Always use an alignment rod to ensure that the entire system is set up correctly. Make sure all surfaces are cleaned and the muzzle device has been torqued and Rockset to the barrel. Use on a Q can voids your warranty be warned. Torque the muzzle device to approximately 15-25 ft lbs. Make sure the muzzle device is square against the shoulder. When setting the silencer on the muzzle device ensure that the threads and tapers are clean. Torque the suppressor to 10 ft lbs. Ensure alignment. Enjoy. Specifications for Rearden MFG FHD HT Flash Hider: Manufacturer: Rearden MFG Color: Heat Treat Finish: H900 Wheat Length: 1.723 in Package Contents: Rearden MFG FHD HT Muzzle Device Rearden MFG 10240: FHD HT Flash Hider 13x1 LH HT Heat Treat