The CompM2 is a battery-powered, non-magnifying red dot type of reflex sight for firearms manufactured by Aimpoint AB. It was first introduced in the U.S. Armed Forces in 2000, designated as the M68 Close Combat Optic. It is also known as the M68 Aimpoint and is designed to meet United States military standards. The sight is designed for use with the M16/M4 family of rifles, but can be mounted on any weapon fitted with an upper Picatinny rail. It is also NVG-compatible—the aiming dot is still visible through night vision scopes and goggles. The Army's M68 designation was also applied to a later version of the sight, the Aimpoint CompM4.
Colt M4 carbine with M68 Close Combat Optic and back-up sight.
A red dot sight is a common classification for a non-magnifying reflector sight that provides an illuminated red dot to the user as a point of aim. A standard design uses a red light-emitting diode (LED) at the focus of collimating optics, which generates a dot-style illuminated reticle that stays in alignment with the firearm the sight is attached to, regardless of eye position.
View through Tasco ProPoint red dot sight (model PDP2ST) on a Ruger 10/22. Made in Japan for Tasco, the ProPoint 2 was one of the first red dot sight models to become widely popular.
Reflex sights have varying dot viewing angles; that is the maximum angle the operators eye can be offset from the center-axis of the sight whilst the dot still remains visible.
Left: Aimpoint Acro C2 reflex sight laying on its side. Right: Acro rail on a Picatinny riser.
A U.S. Marine looking through an ITL MARS combination red dot and laser sight mounted on his M16A4 MWS rifle during the Second Battle of Fallujah, 2004