The 4 x 5.65" Tiffen Night Fog Camera Filter yields a natural fog effect with overall atmospheric softening and wide flare, coupled with unique contrast reduction technology that reduces highlights without darkening shadows. This filter has an effect grade of 1/2. This filter has been manufactured using the Colorcore Technology process that laminates the filter substrate between two pieces of optical glass, then grinds and polishes them to a precise tolerance of 1/10,000" flatness. Made in the USA, the filter has a 10-year Warranty.