The FAST Absolute Riser securely elevates block-type red dot optics with an absolute co-witness height to a 2.26 optical center line. The FAST Absolute Riser provides an elevated M1913 Picatinny platform for direct attachment of optics, such as EOTech XPS, Leupold LCO and other absolute co-witness optics. It can be paired with any FAST FTC (Flip-to-Center) magnifier mount. It comes standard with a two cross bolt rail clamp, but is compatible with the FASTQD (Quick Detach) Lever.Specifications and Features:Model: Fast Absolute RiserMaterial: AluminumPieces: 1Mount Type: Picatinny RailLength: 3.60"