Features:Converts suppressors with 1.375x24 “HUB” threads to Plan B - 1.1875x24 internal threads Material: 17-4 PH stainless steel Finish: Black nitride Precision machined Made in Oregon Backed by our Lifetime Warranty The Stronghold adapter allows you to run Plan-B threaded muzzle devices on any suppressor with a HUB-style (1.375x24) rear thread. Built to exact tolerances, it's the ideal solution for cross-platform suppressor setups.