Yankee Hill Machine Co Universal Suppressor Mount, Coverts HUB Mount to Direct Thread, 5/8-24, Melonite QPQ Finish, Black YHM-2189-24 This 1.375"-24 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 their HUB Direct Thread Mount using a 3/4" open end wrench. Then simply thread the suppressor onto your barrel.