The SightmarkA(R) A-Spec M3 combines a pistol-friendly compact size with automatic brightness control to create the ultimate Reflex Sight for today's concealed carrier. The 3 MOA red dot reticle automatically adjusts in brightness to match ambient light conditions, so you have the right point of aim every hour of the day. The aluminum alloy housing is incredibly durable, IP55 water-resistant, and capable of withstanding the devastating recoil of the .375 H&H cartridge. And with battery life up to 100,000 hours, the A-Spec M3 is guaranteed to help you make your mark. 3 MOA red dot reticle Automatic brightness adjustment gives you the right point of aim for every scenario Lightweight compact aluminum alloy housing IP55 water-resistant rating Shockproof, capable of withstanding up to .375 H&H caliber recoil Up to 100,000 hrs. battery life Co-witnesses with standard pistol sights Fits standard Shield RMSc footprint Includes rubber cover, low-profile fixed mount, and CR2032 battery Order today!