The Stribog Muzzle Extension was designed to be used in conjunction with the KDG SRX models; Stribog Receiver Extensions. These muzzle extensions thread onto the Stribog barrel, extending the end of the muzzle an extra 3 to 6 inches. This device is important for directing the blast of the muzzle forward of the Stribog Receiver Extension, protecting the users' arms and hands during weapon firing and manipulations. Both the SMX3 and SMX6 thread onto the end of the muzzle using standard 1/2A-28 threads and are constructed from a mild C1018 steel so that it can easily be welded, if required, to keep in compliance with local and federal firearms laws and regulations (BOO!). Bolsteri Mfg: Kinetic Development Group Llc