Rugged Suppressors Fixed Mount, M18x1 Thread Pitch, For Use with Obsidian 45/9, Matte Finish, Black OF004 The Rugged Universal Direct Thread Mount allows the Alaskan360 and other suppressors utilizing the 1.375 X 24 thread pattern to mount directly to the barrel of a firearm. The Universal Direct Thread Mount is available in 5 thread pitches and enables the shooter to quickly install a universally threaded suppressor to their firearm.