This universal thick, heavy-duty Picatinny rail sling attachment mount adapter with loop is perfect for your AR handguard rail and forend work with HK sling snap hooks, gun sling clips, and mash hook slings, and it is compatible with most military rifle and shotgun strap gun slings without swivels up to 1.25" in width. The Picatinny rail mount sling adapter is ambidextrous. The compact rail mount sling adapter is secured to the rail with a single hex head screw. It is made from CNC machined, thick aircraft grade aluminum with a matte black hard coat anodized finish. The sling loop hole diameter is approximately 0.50 of an inch.