This Clutch-Lok QD mount doubles as a flash hider for our 5.56MM SLH/SLX suppressors. It offers a quick and simple attachment of your suppressor and reduced muzzle flash when the suppressor is removed. Shoulder Interface: 25-degree taper for use with SIG SAUER Taper-Lok barrels. (A 90-degree version of this item is available for non-SIG SAUER barrels) Please check with your local and state municipalities for any further regulatory requirements. It is your responsibility as the buyer of these components to make sure you comply with all NFA rules and applicable laws. Product Specifications Overall Length: 2.1 inches Threads: 1/2 in - 28 tpi Weight: 3.2 oz Material: Stainless Steel Technology: Clutch-Lok QD Type: Flash Hider Barrel Interface: 25-degree taper Caliber: 5.56 NATO