Trijicons ACOG Advanced Combat Optical Gunsight is a fixed power compact riflescope with an illuminated reticle pattern for use in bright to lowno 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 7075T6 aircraftaluminumalloy housing provides for a nearly indestructible sighting system. Multicoated lenses provide superior clarity and lightgathering capabilities with zero distortion. The ACOG is drynitrogenfilled to eliminate fogging and waterproof to 100 meters. It is shockresistant proven to withstand recoil from 22LR up to 50 BMG and easily passes U.S. military drop test requirements.The 4x32 LED ACOG offers LED reticle illumination powered by a single AA battery. Users can select from six adjustable brightness levels with an off between each setting. The body has been optimized by moving the RMR mount forward to maximize its performance in conjunction with the ACOG. It includes Trijicons TA51 mount which uses two thumbscrews to mount your ACOG to a Picatinny rail.This model has a red LEDilluminated .223 crosshair reticle.