Trijicon Picatinny Rail Mount Adapter for RMR - Lightweight 1/3 Lower Cowitness. This lower 1/3 cowitness mount is perfect for mounting the RMR or SRO on any rifle platform with a Picatinny rail. The AC32062 provides a lower 1/3 cowitness with backup iron sights. This means that the RMR/SRO is mounted higher than the iron sights so that it provides a less cluttered field of view. The iron sights are then in the lower 1/3 of your optical window for backup. Specifications for Trijicon Picatinny Rail Mount Adapter for Trijicon RMR: Manufacturer: Trijicon Color: Black Finish: Matte Fabric/Material: Metal Fit: All Trijicon RMR's not included Co-Witness: Lower 1/3 Red Dot Sights-Footprint: RMR Optic Cut: Not Applicable Length: 1.78 in Condition: New Mount Type: Picatinny Features of Trijicon Picatinny Rail Mount Adapter for Trijicon RMR: Lower 1/3 Cowitness Fits All Trijicon optics using the RMR footprint. See Through Design (helps keep the mount lightweight and improves field of view) Compatible With Any MIL-STD 1913 Picatinny Rail Lightweight Rugged Aluminum Design Distance From Top of Mounting Rail to Optical Axis: RMR: 1.516 in. SRO: 1.757in Package Contents: Trijicon Picatinny Rail Mount Adapter for Trijicon RMR Trijicon AC32059: Picatinny Rail Mount Adapter for RMR - Lightweight 1/3 Lower Cowitness