Ade Advanced Optics Front/Rear 45-Degree Rapid Transition BUIS Backup Iron Sight Same height above bore as standard-issue M4 / M16A4 sights Machined from lightweight, extremely durable 7075 aluminum, Mil-Spec hard anodized 1/2 MOA elevation and windage adjustments Ambidextrous sights easily and securely mount to Picatinny rails using a flathead screwdriver