Just because the light's not perfect doesn't mean your aim shouldn't be(TM). Troy Industries' Tritium BattleSights(TM) are designed to eliminate the poor sight orientation that is typical in twilight. Tritium is a form of hydrogen that emits a continuous light source when batteries or electricity are not available. The front post is centered between two Tritium points of reference to allow proper alignment. Troy Rear Folding Tritium Sights, a permanent, rail-mounted alternative to a standard A2 sight, allow limitless mounting options on all-length rails with a serrated ramp to eliminate glare. Features Sight can be moved or taken off without permanent modification to the firearm. Features snag-free apertures at factory height. Front post is centered between two Tritium points of reference. Technical Specifications Machined from hardened Aircraft Aluminum with stainless steel components and finished in MIL-SPEC hardcoat anodizing. Sight is designed to work on same-plane rail systems only. Will not work with a railed gas block that is higher or lower than the receiver. Front sight must be mounted at the same height plane as the rear sight. Railed gas blocks that are lower than receiver height will not zero properly. Available in Black and Flat Dark Earth.