Multi-Reticle 2 MOA & 65 MOA Circle Open Reflex Sight, QD Auto Lock, Integral High See - through Picatinny Mount, with Internal Battery, Quick Release Mount, co-witness their red dot with their iron sightsAdvanced parallax free lens design, 100% Shockproof, Waterproof and Fog ProofParallax free optical design with unlimited eye relief, Dot Size, 2 MOA, Reticle, 65 MOA Ring/Red DotThe large window size is for reacquire the dot if eye position shiftsLong lasting battery life and it loads from the side instead of bottom for easy battery installation A high-profile mount for the shooter establish a good cheek weld while looking through the sights, co-witness their red dot with their iron sights, it more natural and faster to acquire a target with a taller sightQuick detach mount for standard picatinny or weaver rails CNC machined with T6061-T6 housing