Product Description The Primary Arms SLx MD-21 is an advanced micro dot sight that incorporates the latest technologies and materials to deliver exceptional close-quarters battle (CQB) performance. Weighing only 5 ounces, this lightweight yet rugged optic features upgraded mounting hardware for guaranteed rigidity and precision when you need it most. At the heart of the MD-21 is the versatile ACSS-CQB reticle, offering four selectable modes including a BDC calibrated out to 600 yards for both 5.56 NATO and 7.62 NATO, wind holds, ranging capability, and a CQB horseshoe. The Autolive motion-sensing technology automatically powers down the optic after 2 minutes of inactivity and powers it back on the moment you move it, dramatically extending battery life without sacrificing readiness. Constructed from hardcoat anodized aluminum with a fully multicoated lens, the MD-21 is waterproof and shockproof for reliable performance in harsh conditions. It fits the standard Aimpoint Micro footprint and includes both Lower 1/3rd and Absolute Co-Witness mounts, backed by the Primary Arms Lifetime Warranty. Product Highlights ACSS-CQB reticle with 4 selectable modes (Chevron only, Chevron + BDC, Chevron + Horseshoe, Full Reticle) and BDC holds calibrated out to 600 yards for 5.56 NATO or 7.62 NATO Autolive motion-sensing technology for extended battery life, automatically powering down and reactivating the optic based on movement Night vision compatible with 12 brightness settings, including dedicated low-light and NV-compatible modes Fully multicoated lens for superior clarity and light transmission housed in waterproof and shockproof hardcoat anodized aluminum construction Standard Microdot footprint (Aimpoint Micro compatible); includes Lower 1/3rd and Absolute Co-Witness mounts and is backed by the Primary Arms Lifetime Warranty Specs Brand: Primary Arms MPN: PA-SLX-MD-21-ACSS UPC: 818500018261 Weight: 5 oz Objective Lens Diameter: 21mm Battery: CR2032 (3V Lithium Coin) Brightness Settings: 12 Click Adjustment: 1/2 MOA Finish: Hardcoat Anodized Material: Aluminum Mount Compatibility: Aimpoint Micro, M1913 Picatinny Reticle: Red ACSS-CQB Night Vision Compatible: Yes Warranty: Lifetime Disclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product&';s manufacturer.