The PVS-14 Demist Shield Fog-Resistant Protective Lens snaps onto the eye piece of the unit to prevent condensation from forming on the optics during rapid temperature changes, heavy and/or long use. This low cost lens is cheap insurance to keep your PVS-14 operational. We recommend this accessory for anyone operating in constantly humid or maritime environments as well as those in desert locations where the temperature can change dramatically between dusk and dawn.
