Primary Arms SLx MD-21 Push Button 21mm Microdot w/ AutoLive, ACSS-CQB Red Reticle - PA-SLX-MD-21-ACSS
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Primary Arms SLx MD-21 Push Button 21mm Microdot w/ AutoLive, ACSS-CQB Red Reticle - PA-SLX-MD-21-ACSS is backordered and will ship as soon as it is back in stock.
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Description
Description
Primary Arms SLx MD-21 Red Dot Sight – ACSS-CQB Reticle
The SLx MD-21 takes micro red dot performance to a whole new level with the proven ACSS-CQB reticle—a smart, compact solution designed for everything from point-blank defense to long-range precision. Weighing just 5 oz., this rugged red dot is built for serious shooters who demand speed, accuracy, and durability in a lightweight footprint.
The new ACSS-CQB reticle is a game-changer in the micro dot world. Featuring a precise chevron aiming point, three BDC holds calibrated for 5.56 NATO or 7.62 NATO out to 600 yards, wind holds, and a CQB horseshoe, this optic delivers unmatched versatility. Whether you're clearing rooms or ringing steel at distance, this reticle has you covered. Best of all—you can choose between four reticle modes to match your mission:
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Chevron only
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Chevron + BDC
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Chevron + Horseshoe
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Full ACSS-CQB reticle
The upgraded LED emitter ensures night vision compatibility and daylight visibility with 12 brightness settings, and Autolive™ motion-sensing tech automatically powers down the optic after 2 minutes of inactivity—then powers it back on the moment you move it. Built with fully multicoated glass and a hardcoat anodized aluminum housing, the MD-21 is both waterproof and shockproof to handle harsh environments with ease.
Need a taller mount? Check out the SLx 2.26" Mount (sold separately) for heads-up shooting or night vision use.
Key Features:
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ACSS-CQB reticle with BDC out to 600 yards, wind holds, ranging, and CQB horseshoe
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4 reticle modes: Chevron only, Chevron + BDC, Chevron + Horseshoe, Full Reticle
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Autolive™ tech for extended battery life
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Night vision compatible with 12 brightness settings
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Fully multicoated lens for enhanced clarity and light transmission
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Top-mounted push-button brightness controls
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Waterproof and shockproof aluminum construction
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Standard Microdot footprint (Aimpoint Micro compatible)
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Includes Lower 1/3rd and Absolute Co-Witness mounts
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Backed by the Primary Arms Lifetime Warranty
Specifications:
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Weight: 5 oz
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Battery: CR2032 (3V Lithium Coin)
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Brightness Settings: 12
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Click Adjustment: 1/2 MOA
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Finish: Hardcoat Anodized
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Material: Aluminum
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Mount Compatibility: Aimpoint Micro, M1913 Picatinny
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Reticle: Red ACSS-CQB
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Night Vision Compatible: Yes
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Warranty: Lifetime
Part of the proven SLx series, known for innovation, reliability, and real-world performance. Every SLx optic is field-tested and duty-ready—no guesswork, just results.

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Free Shipping: All orders ship free via UPS Ground/USPS/FedEx which takes 1-5 business days. We also offer UPS 2nd Day air for $9.99.
Same Day Shipping:* UPS only accepts ground shipments on Weekdays. Therefore any UPS Ground order we receive will ship same day if ordered before 2PM EST on Weekdays only.
Hassle Free Returns: We have a 30 day return policy. If you want to return your item for whatever reason just contact us and we'll send you a pre-paid label just like Amazon.
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