Trijicon ACOG, 2X20mm, Dual Illuminated RTR 9mm PCC Reticle, Includes Q-LOC Mount, Matte Finish, Black TA47-C-400387 There's a reason the Trijicon ACOG (Advanced Combat Optical Gunsight) is the official medium-distance engagement optic of the U.S. Marine Corps and U.S. Special Operations Forces. And why more than one million have been produced. Each one is specifically engineered to provide increased hit potential in all lighting conditions, while also providing legendary durability and reliability.