Suitable for models PL70, PL70R, and PL80. Four rugged glass filter discs with a special coating, 1.5mm thick, in four matte-finished polymer collars made of rugged polypropylene. Colour filters can also be used in combination with the white signal cone. Functions: blue for better detection of body fluids (blood, sweat, etc.) red to preserve night vision, yellow for less glare in fog, green for game observation.