Night Fision night sights offer a revolutionary new design that with brighter, more vivid, aiming dots. Like all night sights, Night Fision uses self-illuminating Tritium to get the ''always on'' glow that makes them so effective. Night Fision sights have 30% more Tritium than most sights on the market. The Tritium insert isnt surrounded by a painted-on ring, but rather one made of a daylight fluorescing material that produces optimum visibility in daylight. Night Fision sights provide maximum visibility in both nighttime AND daylight conditions, so when the pressure is on, youll locate your sights more quickly and get them on target - fast. A new mounting system holds the Tritium vial more securely to protect it from the ravages of unexpected knocks and dings.