AT3 RCO Riser Mount for Trijicon MRO Pattern Optics

Cantilever Riser Mount for Trijicon MRO – Absolute or Lower 1/3 Cowitness

The iconic Trijicon MRO comes in many configurations – not all of them optimized for the AR-15. The AT3 RCO Riser mount makes it simple to get the height you need, whether you want to set up for absolute or lower 1/3 cowitness. This is a complete kit, featuring a cantilever riser mount, a height spacer, all necessary screws, and a Torx wrench so you can optimize your MRO.

Light on Weight, High on Value

A cantilever riser mount offers extra benefits for usability over standard, block-style risers. The forward angle pushes the MRO red dot further from your eye, aiding on focusing your vision down the sight tube, making target acquisition simpler. The skeletonized design is durable, lightweight, and modular, all at a price well below most other aftermarket options. Plus, it’s backed by the AT3 Lifetime Warranty.

How to Install

1. Remove any existing mount on your Trijicon MRO by removing the four screws at the bottom of the mount
2. Choose your desired configuration for the RCO riser mount
   • For Absolute Cowitness, use the RCO riser mount and the four supplied short screws (4-48 x 3/16″)
   • For Lower 1/3 Cowitness, use the RCO riser mount with the supplied spacer and four long screws (4-48 x 5/16″)
3. With the RCO riser mount angled towards front of your MRO, install the mount to the optic with the supplied screws
   • We highly recommend using a small drop of Blue Loctite, or equivalent medium-strength threadlocker on each screw prior to installation
4. Now that the mount is attached, install your MRO onto your rifle, tightening the large screw to 20 inch-lbs.
   • Again, a small drop of Blue Loctite or equivalent threadlocker on the large screw is recommended prior to installation

Red dot sight is not included.