Primary Arms SLx MD-21 is a lightweight, night-vision-compatible micro red dot with a 21mm objective and a 2 MOA dot. It features Autolive power-saving technology and upgraded mounting hardware for secure Picatinny attachment.
The Primary Arms SLx MD-21 is a compact micro red dot sight designed for fast target acquisition in close-quarters and low-light environments. It is lightweight and constructed to provide a rigid mounting interface for Picatinny-equipped platforms. Night-vision compatibility and power-saving Autolive technology make it suitable for long-duration use in varied conditions.
Product Specifications
The product type is Red Dot.
The model is listed as Microdot (SLx MD-21).
The reticle is a Red Dot.
The dot size is 2 MOA.
The optical power is 1X.
The objective measures 21mm.
The finish color is Black with an anodized coating.
The unit is designed to fit Picatinny rails.
The sight is specified as Night Vision Compatible.
The sight incorporates Autolive technology to shut off the reticle after inactivity and restore it on motion.
The LED emitter is described as an upgraded unit for true red dot brightness and extended runtime.
The mounting hardware is described as upgraded to provide rigidity and consistent alignment.
The listed weight in the product description is 5 ounces.
The sight is intended for close-quarters and low-light applications such as training or competition.
The UPC is 818500018254.
Compact and purposeful, the SLx MD-21 provides a low-profile aiming solution for close-quarters work and dynamic range drills. Its combination of a small 2 MOA dot, night-vision compatibility, and motion-activated power saving makes it a practical optic for shooters who prioritize lightweight equipment and consistent, repeatable mounting. The upgraded hardware and emitter support reliable on‑gun performance across extended use.
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