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Primary Arms GLx MD-21S 1x Micro Reflex Red Dot Sight, Color: Black, Battery Type: CR2032, Lithium Metal, Up to 23% Off w/ Free S&H — 2 models

Primary Arms GLx MD-21S Micro Reflex Red Dot Sight, 1x, 2 MOA Red Dot Reticle, Black, 810025
Primary Arms GLx MD-21S Micro Reflex Red Dot Sight, 1x, 2 MOA Red Dot Reticle, Black, 810025
Primary Arms GLx MD-21S Micro Reflex Red Dot Sight, 1x, ACSS-CQB Red Dot Reticle, Black, 810026
Primary Arms GLx MD-21S Micro Reflex Red Dot Sight, 1x, 2 MOA Red Dot Reticle, Black, 810025
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Primary Arms GLx MD-21S Micro Reflex Red Dot Sight, 1x, 2 MOA Red Dot Reticle, Black, 810025
Primary Arms GLx MD-21S Micro Reflex Red Dot Sight, 1x, 2 MOA Red Dot Reticle, Black, 810025
2 of 3 images
Primary Arms GLx MD-21S Micro Reflex Red Dot Sight, 1x, 2 MOA Red Dot Reticle, Black, 810025
Primary Arms GLx MD-21S Micro Reflex Red Dot Sight, 1x, ACSS-CQB Red Dot Reticle, Black, 810026
3 of 3 images
Primary Arms GLx MD-21S Micro Reflex Red Dot Sight, 1x, ACSS-CQB Red Dot Reticle, Black, 810026

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Questions & Answers
Can it be used on the Taurus Raging Hunter in 460 10in barrel? Expert Answer

Yes, it will work but places the dot very high over the bore. You might consider a mini red dot like the Holosun HS407COMP-GD-6 https://www.opticsplanet.com/holosun-hs407comp-gd-6-1x-1-1x0-87-in-reflex-red-dot-sight.html and pair it with a base for your revolver https://www.opticsplanet.com/holosun-407c-507c-508t-pic-rail-mount.html

by Stevey GB, Gear Expert, July 16, 2026
what is the mounting footprint?

According to PA it's a standard microdot mount

by Fred, Verified Owner, January 23, 2026
View All Q&A You Have a Question? Ask!
Customer Reviews
Helpful Positive Review
Built Well by Q, Verified Owner, May 30, 2025
I have not had the chance to run this optic through any testing, but it is built well. The materials feel sturdy and I am excited to see how it holds up.
3/11 found this helpful
Helpful Positive Review
good red dot by BIG BORING, Verified Owner, January 21, 2026
It’s a good red dot compared to others on the market. It’s mid priced and has many features such as 3 different retitles, up and down button for brightness, and reserves battery life with solar power
1/1 found this helpful
Helpful Negative Review
Horrible halo/glare by blarg, Verified Owner, October 25, 2025
Tried both the GLx and SLx versions of these and they have horrible halo ring. You also get it around the red dot when turned up only like half way. Not sure why PA would put their name on this.
4/12 found this helpful
Most Recent Reviews
Primary Arms GLx MD-21s by Grimey556, Verified Owner, August 21, 2026
Phenomenal optic very crisp and clear under a Holosun 3x magnifier. I like the different reticles that you can choose. I love that it uses the T1/T2 footprint so you have a multitude of different mounts that you can run. My only complaint is that whe...
Read More...
Most Recent Reviews
GLx MD-21S by Ed, Verified Owner, August 2, 2026
Worth every penny, fast shipping and really nice sight with a really cool reticle
Most Recent Reviews
GLx MD-21S by Grimey556, Verified Owner, August 1, 2026
Love this red dot seems to be very reliable with positive clicks when zeroing the Red Dot. Crisp and clear under magnification and no glare. Perfect height for 1/3 Co Witness mounts and uses T2 footprint. Love the multiple reticle options. Just like ...
Read More...
Read All 7 Reviews

14% OFF Red Dot Sights

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Product Info for Primary Arms GLx MD-21S 1x Micro Reflex Red Dot Sight

The GLx MD-21s is a high-performanceimage

micro dot optic, built for superior agility

and precision from close-quarters to

intermediate range. This red dot features

an advanced solar failsafe system,

supplementing your power supply to

ensure the optic operates with maximum

runtime. In addition, this optic features

fully upgraded lenses, a new ultra-bright

emitter, intuitive push-button controls, and

our heavy-duty mount system.

Specifications for Primary Arms GLx MD-21S 1x Micro Reflex Red Dot Sight:

Manufacturer: Primary Arms
Color: Black
Magnification: 1 x
Illumination Color: Red
Battery Type: Lithium Metal, CR2032
Red Dot Sights-Footprint: Not Applicable
Condition: New

Features of Primary Arms GLx MD-21S 1x Micro Reflex Red Dot Sight

  • Autolive
  • Multi-coated Lens
  • Multi-reticle select
  • Push-button controls
  • Red dot bright
  • Shockproof
  • Solar backup
  • Waterproof

Package Contents:

  • Primary Arms GLx MD-21S 1x Micro Reflex Red Dot Sight

Primary Arms GLx MD-21S 1x Micro Reflex Red Dot Sight Orderable Models

List of Orderable Models

  • Primary Arms GLx MD-21S Micro Reflex Red Dot Sight, 1x, 2 MOA Red Dot Reticle, Black, 810025 , MPN: 810025 , UPC: 818500018278 , Code: 29R-RD-GLXMD21S-810025
  • Primary Arms GLx MD-21S Micro Reflex Red Dot Sight, 1x, ACSS-CQB Red Dot Reticle, Black, 810026 , MPN: 810026 , UPC: 818500018285 , Code: 29R-RD-GLXMD21S-810026

Primary Arms GLx MD-21S 1x Micro Reflex Red Dot Sight Unavailable & Discontinued Models

List of Unorderable Models

  • DEMO, Primary Arms GLx MD-21S Micro Reflex Red Dot Sight, 1x, ACSS-CQB Red Dot Reticle, Black, 810026 , MPN: 810026-DEMO , Code: 29R-RD-GLXMD21S-810026-DEMO-OB-A
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Last updated 2026-09-08 UTC.