CMMG ZEROED HUB Mount, Direct Thread 1/2x28 to HUB 1.375-24, Nitride Finish, Black 11DB017 Sometimes there's no better way to do it than to keep it simple, and it doesn't get much simpler than direct threading your suppressor on. Made to attach to firearms with a 1/2x28" muzzle thread, CMMG direct thread mounts are compatible with any 1.375-24" HUB pattern threaded suppressors.