Kingslayer is a super compact open reflex dot sight allowing you to quickly acquire a sight picture with both eyes open while focusing on the target. For pistol slide platforms, remove the included 1913 Picatinny mount and use the RMR-compatible footprint underneath. With the Picatinny mount installed, Kingslayer works great on rifle and shotgun applications. Kingslayer is waterproof, fog resistant and features a scratch resistant, anti-glare lens multicoating. Built like a tank, Kingslayer will maintain its zero on reciprocating pistol slides, 12 gauge shotguns and even .308 battle rifles. Choose from 3 MOA red dot, red circle dot, or green circle dot reticles. RMR Footp Mfg: Swampfox Optics