Known by model number, the NIVISYS Industries NSV-80 simply, quickly and accurately clips onto the 1913 Picatinny rail in front of a telescopic sight to turn a daylight system into a night fighting system. The NSV-80 (night vision sight) does not require operators to have error prone separate night and day zeros on their telescopic sights. The NSV-80 simply mounts in front of most telescopic sights via a quick-detach Picatinny compatible clip on mount. While not always required, the NSV-80 also features a rear rubber seal (Litegard) that fits between the scope's objective lens (or sunshade) and the NSV-80 to eliminate or limit peripheral light. The NSV-80 internal optics makes an accurate full-field view possible even if it is NOT in alignment with the telescopic sight's objective lens. In other words, if the reticle is in view, the NSV-80 reticle is still on target without further adjustment. No need for potential zeroing errors when converting from day to night operations. NIVISYS' NSV-80 provides a clear and precise parallax-proof conversion from day optics to dark time without any scope adjustments.