Bobro Engineering Trijicon MRO Riser Lower 1/3 Co-Witness Black. The system is modular and can utilize offset risers as well as cantilevered risers. The riser features rear serrations to minimize glare. Like all BLAC mounts the lever can be mounted any side or direction. When just using the low base lever can only be used on the left side. The Trijicon MRO Mount comes with all tools necessary for installation. Included Accessories: Instruction and Toolkit Specifications for Bobro Engineering Trijicon MRO Riser: Manufacturer: Bobro Engineering Color: Black Length: 4.75 in Height: 2.5 in Width: 2.5 in Package Contents: Bobro Engineering Trijicon MRO Riser Bobro Engineering B19-555-003: Trijicon MRO Riser Lower 1/3 Co-Witness Black