AT3 Tactical RCO Riser Mount for Trijicon MRO Pattern Optics


Click Here for Price
Out of Stock

Join the waitlist to be emailed when this product becomes available

Orders will Ship within 1 Business Day
NCSTAR .223 Remington Laser Bore Sight - AT3 Tactical

NCSTAR .223 Remington Laser Bore Sight


Magpul MBUS PRO Front and Rear Back-Up Sight Kit

Magpul MBUS PRO Front and Rear Back-Up Sight Kit


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.

The RCO mount makes both your optic and rifle look better

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.


  • Material: 6061-T6 Aluminum
  • Finish: Hardcoat anodizing
  • Fit: MRO Pattern Optics
  • Mounts to: Picatinny Rails
  • Weight: 1.1 oz
  • Includes
    • Torx Wrench
    • 4-48 x 3/16″ Screws (x4)
    • 4-48 x 5/16″ Screws (x4)

Have Questions About this Product?

The AT3 Tactical store has a 90 day no-hassle return policy for products in good condition. You can view the full details of our return policy here.

If you encounter an issue or defect with a product after 90 days of your purchase, you can refer to the manufacturer for a warranty claim. Their policies are below.

AT3 Lifetime Warranty Logo

All AT3 Tactical Brand Products carry a lifetime warranty against manufacturer’s defects.

This includes AT3 Red Dot SightsHandguardsIron Sights, and any other product that carries the “AT3 Tactical” or “AT3™” name. For other brands (ex. Magpul or Troy), please refer to the manufacturer’s warranty policy.

In the event that your AT3™ product becomes unusable, we will repair or replace the product at no charge to you.

If we cannot repair your product, we will replace it with a product in perfect working order of equal or better physical condition. The warranty is fully transferable, but we may require information about the original purchase to validate the authenticity of the product.

If your product is in need of warranty service, please contact AT3 Tactical to start the process

Our contact info is available here. To expedite processing, please provide your order information and description of the defect.

Please note: The AT3 Lifetime Warranty does not cover loss, theft, intentional damage or cosmetic damage that doesn’t affect the performance of the product.