Unity Tactical Fast Pro Mount Black. 26 optical centerline from the rail. It is also compatible with the optics of industry standard 30mm footprint. It features a built-in fully adjustable rear back-up iron sight that is compatible with a standard front sight for a traditional sight radius. Very compact it covers only three slots on an M1913 Rail. It comes standard with a 2 cross bolt rail clamp and can be paired with any FAST FTC (Flip-to-Center) magnifier mount. Specifications for Unity Tactical Fast Pro Mount: Manufacturer: Unity Tactical Finish: Type 3 Hard Anodized Fabric/Material: 7075-T6 Aluminium Height: 2.26 in Condition: New Unity Tactical FSTPROB Fast Pro Mount Black 7075-T6 Aluminum Unity Tactical FSTPROB: Fast Pro Mount Black