The Aimpoint Comp series of red dot sights are designed to be compact scopes capable of handling unfriendly conditions and recoil from the largest calibers available. Aimpoint CompC3: A basic red dot sight with a 2 MOA dot. Perfect for use on rifles, bows, and pistols. Comes with a single 30mm ring for mounting on Weaver/Picatinny rails. Rugged enough to withstand abuse and recoil, affordable enough for your favorite rifle. Aimpoint CompM2: This red dot sight is the standard by which other red dot sights are measured. The CompM2 has been in use by the US armed forces since its inception, and is compatible with all generations of night vision. Battery life can range between 10,000 hours and 100,000 hours of continuous use, depending on brightness. Waterproof to 80 feet. Aimpoint CompM3: Similar to the CompM2, this upgraded version offers five times the battery life of its predecessor, as well as a body submersible to 135 feet. Choice of 2 MOA or 4 MOA. Aimpoint CompML3: A version of the Comp ML3 without night vision compatibility. Aimpoint CompM4: A standard AR spacer and QRP2 mount are included with this red dot sight, negating the need for scope rings. The Comp M4 is compatible with all versions of night vision, but functions best with third generation night vision devices. Aimpoint CompM4s: Identical to the CompM4 with the battery compartment moved to the lower right of the scope for better visibility.