Trijicon ACOG 3.5x35 LED Illuminated .223 Crosshair Reticle with TA51 Thumbscrew Mount, Red Red LED Illuminated .223 Crosshair Reticle RUGGED ALUMINUM-ALLOY HOUSING: Forged 7075-T6 aircraft-aluminum-alloy housing provides for a nearly indestructible sighting system SUPERIOR QUALITY GLASS LENSES: Multi-coated lenses provide superior clarity and light-gathering capabilities with zero distortion FIXED MAGNIFICATION: Fewer moving parts than a variable optic equals more durability "BOTH EYES OPEN" DESIGN: The ACOG can be used as a CQB sight when shooting "both eyes open," utilizing the Bindon Aiming Concept