The WAdvanced Combat Optical Gunsight (ACOG) is a series of telescopic sights manufactured by Trijicon. The ACOG was originally designed to be used on the M16 rifle and M4 carbine, but Trijicon has also developed ACOG accessories for other firearms. Models provide fixed power magnification levels from 1.5× to 6×.
The United States Army, Air Force and Marine Corps field the Trijicon TA31RCO ACOG, a 4× magnification model with 32mm optics (4×32), with specially designed ballistic compensating reticles that are fiber optic & tritium illuminated, for the M4 carbine and M16A4 rifle. This sight is designated the M150 Rifle Combat Optic in Army service and AN/PVQ-31 Rifle Combat Optic in the Marine Corps.
"A 4x magnification scope for medium range engagements."
— In-game description
The 4x M150 is an optical sight featured in Insurgency: Sandstorm.