The Taper Mount PLAN-A adapter provides a Griffin Taper Mount interface for Silencerco Hybrid, OMEGA, and Harvester 338 as well as DEAD AIR ARMAMENT NOMAD, and other suppressors with mount interface inside diameter threading of 1.375x24. No proprietary tools required. Machined in Griffin Armament's Watertown headquarters from billet 17-4 stainless steel, this adapter provides a precision made interface that gives you access to nationally recognized Griffin Taper Mounts and accessories. Precision, durability, and value are at the core of Griffin product design and manufacturing. This product allows you to affordable kit up with the best muzzle devices in the industry. Features17-4 PH SS Billet MachinedBlack Nitrided2.3 Ounce WeightTaper Mount Repeatability and versatility