AAC's 3-inch Picatinny Accessory Rail is made of Type 3 hard coat anodized 6061-T6 aluminum and the mounting hardware (nut/screw) is made of stainless steel. A snag-resistant design and 5-slots complement perfectly the AAC SquareDrop Handguard, or any Keymod handguard. Full-featured dual recoil lugs ensure long-term durability and solid lock-up. Comes with nuts and screws pre-assembled to simplify attachment and includes an install wrench.