The first reflex sight in the world designed for close quarter combat the Mepro M21 by Meprolight has been combat-proven by one of the most elite fighting forces in the world: The Israeli Defense Forces. The reflex sight has a large display that allows shooters rapid target acquisition with both eyes open. Reticle illumination is achieved by a protected fiber optic light collection system during the day and by a self-powered tritium light source at night.Transition between the two systems is instantaneous and automatic to assure good contrast between the aiming dot and the target area. The M21 is night vision compatible and does not require switches or batteries.Features / SpecsManufacturer Number: M21 BReticle: BullseyeBattle proven reflexive to use deadly accurate and totally reliableFeatures large 30mm diameter lens which allows rapid target acquisition with both eyes openRugged armor-protected design operates under all weather and temperature conditions Parallax-freeReticle illumination is achieved by the protected fiber optic light collector system during the day and by the miniature self-powered tritium light source at nightTransition between the two systems is instantaneous and automatic to assure good contrast between the aiming dot and the target areaNight vision and magnifier compatibleTritium Illumination is warranted for 10 yearsWeight: 13.1219 ozLength: 4.48819 inchesWidth: 2.16535 inchesHeight: 2.75591 inchesBlack and grey finishIncludesDust coverQuick-release Picatinny mount that retains zero