Provides Extremely Fast, Heads Up Target Engagement For Close Quarters & Long Range Shooting

Flush-mounted control buttons positioned on the left side of the unit ensure easy, fast access when back-up iron sight or EOTech Magnifier is installed. Integral mount with knurled cross-bolt locks securely MIL-STD 1913 Picatinny and Weaver-style rails; zero is repeatable to 1 MOA after removing and re-mounting. Front one-third of the base underside is elevated .275" (7mm) for clearance over delta ring and standard military-style plastic handguard. Submersible to 33 ft. depth. Models 516 and 556 occupy only 3¼" of rail space, leaving adequate room for a backup iron sight. Both have an easy-to-acquire tactical reticle with a 1 MOA dot inside a 65 MOA ring and provide up to 1,100 hours of continuous operation on two (2) 3 volt CR123A lithium batteries, included. Model 556 is also compatible with Gen I-III+ night vision systems; 1000:1 night vision brightness range with NV switch engaged. Model 517 is powered by two common 1.5 volt AA batteries for 600 hours of continous operation with alkaline batteries or 1,000 hours with lithium cells. Reticle is a 65 MOA circle with a 1 MOA center aiming dot. Requires 3¾" of rail space. Buttons positioned on left side of housing for easy access when G23 Magnifier is mounted behind sight.