AT3™ DELTA 3x Red Dot Magnifier with QD Flip-to-Side Mount


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The DELTA has better glass clarity, longer eye relief, and an excellent QD mount!

The DELTA is AT3’s new red dot magnifier, boasting a long 3 inch eye relief, a broad field of view, and enhanced clarity for making accurate, long-range shots with your red dot sight. This magnifier works with any red dot sight with absolute or lower 1/3 cowitness using the included spacer, making it perfect for enhancing your AR-15. Plus, you can swap this magnifier between rifles easily with the included quick detach mount, with a ratcheting adjustment that ensures a tight, secure fit on your rail.

We recommend pairing the DELTA with our ALPHA red dot sight, for a fully featured, modern red dot and magnifier setup. You can get the ALPHA and DELTA as a set here, with a bundle discount to enhance your rifle, and prepare you for any shot from point blank to 500 yards or more!

Better Eye Relief and Sight Picture

  • A full three inches of eye relief ensures you’ll have a clearer view of the target, even with backup iron sights installed!
  • Multicoated glass gives you a more crisp view of your target, with better light transmission and definition.
  • 38 foot field of view gives you a clear picture of what’s around your target, with a forgiving eyebox for head movement.

Flexibility Between Rifles

  • The Quick Detach Mount is our best yet, with an audible ratcheting adjustment for tight, consistent installation.
  • Switch the Delta between multiple rifles with the fast QD lever, and ensure your red dots have magnification when you need it.
  • Out of the box Absolute Cowitness height – and with the Cowitness Spacer, Lower 1/3 Cowitness for even more optics compatibility.

Durable and Rugged

  • Solid steel lockup in the mount keeps the magnifier secure without the need for a release button or lever.
  • Rubberized shroud keeps the magnifier protected from bumps and scratches in the field.
  • Durable enough to handle recoil from high caliber rifles, shotguns, and even .50 BMG. Yeah, we went there.
  • For anything else, you’re covered under AT3’s Lifetime Warranty. If there’s an issue, we’ll take care of you.

Inside the box

  • DELTA Red dot magnifier with QD Mount
  • Cowitness Spacer
  • Instruction sheet
  • Lens cloth
  • 3mm Allen Wrench
  • Longer Screws for Spacer


  • Magnification: 3x
  • Objective Lens Diameter: 20 mm
  • Height: 1.43inches/36.5mm from the base to center of the optic (Absolute Cowitness)
    • With the use of the Lower 1/3 Cowitness spacer, height is 1.57in
  • Eye Relief: 3.07 inches/78.2mm
  • Exit Pupil: 6.7mm
  • Field of View: 7.28°/38.3 ft @ 100 yds
  • Length: 3.98 inches/101mm
  • Weight: 12 oz. with mount
  • Optics Coating: Fully multi-coated
  • Waterproof Rating: IPX7
  • Housing Material: 6061-T6 anodized aluminum
  • Finish: Hardcoat Anodized
  • Included in the box: QD flip to side mount, 3X magnifier, Cowitness spacer with mounting screws, Tools, Lens Cleaning Cloth,

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.

Customer Reviews

Based on 4 reviews
Charlie Onan
Easy Install & Works

Install took seconds. Quality is up there with magnifiers that are 5x the cost.

Great review! The AT3 DELTA 3x Red Dot Magnifier with QD Flip-to-Side Mount is a great quality magnifier that is easy to install and works great. We highly recommend it!

Joshua Farkash
Where Quality meets Price

First thing you notice out of the box is the quality and rigidity of this magnifier. I'd argue its better in that regard than its Eotech counterpart. Glass seems to be high quality and it's noticeably shorter than other 3x magnifiers. Just about ready to go out of the box! Someone clearly put a lot of time and money into this. I will be running it on my Tavor X95 but seems great for anyone running a red dot on their rifle

Thank you for the great review of the AT3 Delta 3x Red Dot Magnifier! We're glad to see that you're happy with the quality and rigidity of the magnifier, and we're excited to see how it works on your rifle.

Joe A.
Love the Delta 3x

Great eye relieve and matches perfectly with my AT3 optic. This new flip to side mount is super easy and I love the quick release. Took it out to the range last weekend and had no issues. I fully recommend it. Also, AT3 has great service. They’ve been there whenever I needed them and fully resolved any issues.

Thanks for the great review! We're glad you're enjoying your Delta 3x magnifier. The new flip-to-side mount is a great convenience, and we're happy to hear that it works well and resolves any issues you may have had. Thanks again for writing a great review!

Best value in class

I have been looking at several 3x magnifiers at this price range. After thorough research, I can confidently say that this is the best value in class. The glass is clear and crisp. The built is streamlined and rugged. The QD mount is tight and easy to use. Where this optic really shines is the most efficient use of space and the length of eye relief. It is considerably shorter than many competitors, allowing for the most efficient use of rail estate. Moreover, the way the magnifier's flip-to-side mechanism is designed, there is plenty of clearance for a backup rear flip sight to be deployed. You can install this magnifier literally abutting the rear flip sight, and there will be no issue for the backup sight to clear once this magnifier is off to the side. This compares extremely favorably to a few popular competitors.

And now for the most impressive feature: eye relief. At 3 inches (measured exactly as claimed), this is just unsurpassed in its price class. You will definitely notice the difference with the competitors, at a minimum because you won't be hitting your nose on the charging handle 😀

In all, I consider this magnifier a perfectly executed engineering solution and, as a result, the best value for your money in its class.

Thank you for sharing your feedback! We're glad you are satisfied with your purchase!