Featuring precision-machined 17-4 stainless steel construction with a wear-resistant QPQ nitride finish, the Griffin Armament CAM-LOK® Barrel Adapter is a patented universal QD piston attachment system designed to provide a rapid, secure attachment point for your CAM-LOK piston-equipped suppressor. This adapter offers 3 mounting positions with 120° of separation for rapid suppressor installation and removal while a forward taper surface locks in place with suppressor pistons to help mitigate or eliminate the risk of baffle/end cap strikes. Plus, top-cut coarse threads offer enhanced durability and longevity, protecting against galling, cross-threading, and other potential thread damage. .578x28 threads.