The Troy Folding Battle Sights have set a World Standard for design and quality by which all other Back Up Iron Sights are judged. They are easily installed and position the apertures at the exact same height as the factory sights. With no levers or springs to fumble with, deployment of the sight under stress is easy. The robust stainless steel cross locking system ensures your sights will remain up and zeroed in the most extreme combat conditions. To fold simply press the release button located on the left side of the sight. All Troy Sights feature a zero-canting attachment system for use on all military and aftermarket receivers. No tools are required for adjustment. Blackened Stainless Steel and MIL-SPEC Type III Hard Coated T6 Aircraft Aluminum construction.