This Yankee Hill Machine HUB Direct Thread Mount will convert HUB compatible suppressors to a direct thread mounting system. To install, simply remove your existing mount mechanism from your suppressor and thread on the HUB Direct Thread Mount using a 3/4" open end wrench, then simply thread the suppressor onto your barrel. Features17-4PH Heat Treated MaterialBlack Oxide375"-24 Mounting Threads.45 Cal BoreWeight: 1.7 ozAvailable in a variety of thread sizes for various firearms NOTE: YHM-2189-M24X1.5 - "NOT FOR AK", as this is designed to mount to the shoulder of the barrel, not the crown.