This quick-release cantilever mount is designed for mounting telescopic sights with 30mm tubes onto a flattop style AR-15 rifle. The offset of this cantilever mount positions the scope in a forward location, providing correct eye relief and head placement when used on an AR-15. The Precision Optic Mount is precision CNC machined from a block of 6061 T6 aluminum and finished in hard coat type 3 mil-spec anodized black for a rock hard lasting finish. Precision machined from 6061 T6 aluminum. Hard coat Type 3 Mil-Spec anodized for a lifetime of performance.