Noga New Design GDT Ar15 Ar 15 Front and 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 100% New Brand