Primary Arms SLx MD-25 Rotary Knob 25mm Microdot Gen II with AutoLive - 2 MOA Red Dot

Manufactured by Primary Arms
MPN: 810032
Manufactured by Primary Arms
21 Reviews

In Stock

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This Primary Arms red dot sight is part of the SLx optics line. SLx optics have built a reputation for innovation, reliability, and value. All SLx optics undergo rigorous field-testing during development to best serve you in any environment.

The Primary Arms SLx MD-25 Gen 2 Microdot now comes with AutoLive, improving the functionality of an already amazing red dot sight. Stretch that already insanely long battery life even further and remove that fear of picking up your rifle and the dot not being there. With this red dot sight, the moment you pick up your rifle, the dot will turn on and be ready precisely when you need it. After sitting motionless for a brief period of time, the red dot will shut off and conserve battery. Still featuring the same lightweight and durable design with a field of view that rivals larger 30mm red dots, the MD-25 Gen 2 is a no-brainer upgrade to add to your collection.

  • AutoLive functionality
  • Wide field of view
  • Compact, lightweight, and durable
  • Crisp 2 MOA red dot
  • Up to 50,000 hour battery life (5+ years) at medium setting
  • Uses one CR2032 battery (included)
  • Next generation ruggedized mounting system
  • Includes risers and spacers for mounting to 0.96”, 1.41”, 1.54”, or 1.64” central height
  • Compatible with standard micro mounts
  • Fully multi-coated anti-reflective lenses
  • 12 Illumination settings for bright days and night vision compatible
  • Just 3" long and 6.5 Oz.
  • Fog resistant

The Gen 2 SLx 25mm Red Dot been equipped with the next generation ruggedized mounting system. Everything about these mounts has been upgraded from materials and finish to the design in order to create a mount that will not just clamp securely to your rail, but stand up the rigors of real-world use. Integrated recoil lugs help lock your mount in place against the heaviest recoil while large diameter crossbolts give you significantly improved clamping power and will hold up to significant torque. The included riser is the perfect height for AR-15s and AR-10s, but can be easily removed to for installation on AKs, shotguns, and more.

The SLx 25mm Gen 2 red dot includes the low base, a standard riser, and two different height spacers, as well as appropriate mounting hardware. With just the low base, a central height of 0.96” can be achieved. Add the standard riser for 1.41”. With the riser and thin spacer, your central height will be 1.54”. Using the thick spacer will place the optic at 1.64” height. With these options you can easily configure your optic to perfectly match your firearm and shooting style.
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Battery Life50,000+ Hours
Battery TypeCR2032 3V Lithium Coin
BrandPrimary Arms
Brightness12 Settings
Click Value1/2 MOA
FinishHardcoat Anodized
Mount CompatibilityAimpoint Micro
Night Vision CompatibleNight Vision Compatible
Optic SeriesSLx
Reticle2 MOA Dot
Reticle ColorRed
Weight6.5 oz.
  • Product Overview: SLx MD-25 Gen II
California Prop 65 warning

 WARNING: This product can expose you to chemicals, which are known to the State of California to cause Cancer and Reproductive Harm. For more information go to

Ratings & Reviews

21 reviews

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This is the first red dot I have owned. I was hesitant to get one because I was told astigmatism caused issues sometimes . I have no issues with this one. Easy to see and adjust. Very happy with my purchase.


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This sight is amazing. It shot tighter groups than my holosun 512. The dot is super crisp. The glass is super clear. Outside shooting was a breeze, had it zeroed in under 10 shots and put over 200 rounds on it and it held zero and a nice tight group, shot the red bullseye out on multiple targets. I highly recommend primary arms optics. Great optic at a really great price. A+

Excellent Budget RDS


Was in the market for a decent RDS for the wife's AR (range use, mostly).
Was so pleased with the PA SLX 1x Micro Prisms I recently purchased for myself, I decided to explore PA possibilities.
The MD-25 Gen II checked all the boxes so took a chance.
Glad I did, everything looks & functions great and most importantly, the wife likes it.
Installation was a breeze, glass is clear, dot is crisp & well defined, and the rotary knob is *much* easier to rotate than on my Micro Prisms (my only complaint with the Micro Prisms). 1/2 moa adjustments makes for an easy sight-in and the AutoLive feature really extends battery life while maintaining instant readiness.
If durability & longevity match the apparent quality, this is an excellent budget RDS for the price!

Light and reliable

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I've got this on a Marlin .44 magnum leveraging. After hundreds of full house loads it hasn't lost zero and turns on whenever I pick it up, just as designed. I'm an iron sight enjoyed but in darkness or low light, such as the last shoot able hunting light, this thing wins.

Outstanding Red Dot

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Didn’t hear about Primary Arms till a friend told me. Ordered some parts for a build and was really satisfied with how prompt the ship and how helpful they are before and after the sale.
I purchased a new Red Dot for another AR and think it’s one of the finest I’ve seen at any price. It’s the SLX-25 and it’s a great little sight. I was reluctant to buy it because of its size, but It looks a whole lot bigger than it is.
I’ll continue to us PA because of the people as much as their products.

Not what I expected

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Easy to install, glass is clear but the red dot is like a starburst, feels like I have stigmatism. I don’t know but it feel like I’m disappointed compared to other optics that I have.

great value


I loved this optic right out of the box. Super clear glass. I have slight astigmatism but the dot is still insanely sharp. Best bang for the buck at this price point.

Great Red Dot

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Great red dot and love the autolive feature.

Gen II SLX MD-25

by -

This is a great red dot with a price that’s right. The view is big and clear and the autolive feature of the Gen II model has me thinking I may need anther one.

Great optic!!!

by -

This optic is everything I was looking for. The dot is bright, the glass is crystal clear, and most importantly, it holds zero. It gives me consistent hits on steel out to 400 yards on my AK 74. All without breaking the bank. Thank you Primary Arms!!