Trijicon's ACOG (Advanced Combat Optical Gunsight) is a fixed power, compact riflescope with an illuminated reticle pattern for use in bright to low/no light with legendary durability and reliability. Every feature of its design was chosen for a single purpose, to provide increased hit potential in all lighting conditions. Fewer moving parts than a variable optic equals more durability, and the forged 7075-T6 aircraft-aluminum-alloy housing provides for a nearly indestructible sighting system. Multi-coated lenses provide superior clarity and light-gathering capabilities with zero distortion. The ACOG is dry-nitrogen-filled to eliminate fogging and waterproof to 100 meters. It is shock-resistant, proven to withstand recoil from 22LR up to 50 BMG, and easily passes U.S. military drop test requirements. Favored by competitive shooters, the TA11 (3.5x35mm) model provides lightning fast target acquisition and superb optical clarity. This ACOG features a dual illuminated green crosshair 308 ballistic reticle calibrated to 1200 meters. It includes a TA51 flattop adapter mount.