An alternative to traditional sights, Pro I-DOT sights encourage accurate, instinctive sight alignment without taking the time to line up a three-dot sight picture. Simply position the top dot directly above the bottom dot on the target and squeeze the trigger! Tritium inserts and photo luminescent front-sight outlines make these sights visible in all light conditions - day or night. GlockA(R) set features a green rear dot and a green front sight with a lime-green outline. Mfg: Ameriglo