Kastle Group EXPS-226 Optic Riser Black. co-witness optic riseroffers a 2.26 in optical centerline height which promotes a heads-up posture for faster target acquisition. It is designed for use with the EOTECH EXPS series and similar lower ? co-witness optics. The EXPS-226 features our patented titanium KastleClamp mounting technology. Specifications for Kastle Group EXPS-226 Optic Riser: Manufacturer: Kastle Group Finish: Type III Hard Anodized Mil-Spec Fabric/Material: 7075-T651 Aluminum Features of Kastle Group EXPS-226 Optic Riser M1913 Picatinny Riser Lower 1/3 Co-Witness Optics 2.26 in Optical Centerline Titanium K-Clamp Mounting Tech Type III MIL SPEC Hardcoat Anodized Package Contents: Kastle Group EXPS-226 Optic Riser Kastle Group EXPS-226-BLK: EXPS-226 Optic Riser Black