Armed Ops Tactical Rifle Rear Folding Back up Iron Sight Buis Flip up Folding Ar15 Sight is designed to work on same-plane rail systems only obust cross locking system ensures your sights will remain up and zeroed in To fold the battle sight simply press the release button located on the left side of the sight features a zero-canting attachment system, good quality back up sight MIL-SPEC Type III Hard Coated T6 Aircraft Aluminum construction