The Vortex 30mm Precision QR Extended Cantilever Mount With 2" Offset is designed for mounting 30mm optics on flattop AR-15s. Engineered to provide optimum height and eye relief, the Vortex 30mm Precision QR Extended Cantilever Mount With 2" Offset is a one-piece, aluminum mount, with integrated rings - no need for an extended riser or separate rings. Precision machined from 6061 T6 aluminum Hard coat Type 3 Mil-Spec anodized Positions center of scope 1.45" above the rail The Vortex 30mm Precision QR Extended Cantilever Mount is a rock-solid optics mounting platform with a dual release lever system that securely grabs the rail in two places a Mfg: Vortex Optics