The Tiffen 4 x 5.65" UV 16 Filter is a general-purpose clear filter that helps absorb ultraviolet light and reduce the blue cast of daylight. This filter is particularly useful when shooting at high altitude or near large bodies of water. It adds no additional colouration or contrast, allowing you to pair it with other filters. This filter attenuates approximately 89% of UV rays, slightly less than a UV 17 filter. The UV filter is also useful as a general protective filter to be left permanently on lenses. Filters help reduce dust and moisture that could reach your lens element and provide additional protection in case of drops or situations where scratches might occur. Tiffen filters are manufactured using ColorCore technology; a process that involves laminating the filter substrate between 2 pieces of optical glass and grinding it flat to a tolerance of 1/10,000th of an inch. This filter measures 4 x 5.65" / 101.6 x 143.5 mm. - Absorbs 89% of UV light and reduces the blue cast of daylight. - The clear filter adds no additional colouration or contrast, allowing you to pair it with other filters. - General protective filter reduces dust, moisture and scratches that could reach lens elements. Features