Zykkor MC UV Multicoated Ultraviolet Optical Glass Filter 49mm High Quality Optical Glass Multicoated UV Filter Protects your camera lens from dust, moisture, scratches and fingerprints Reduces haziness or fogginess created by ultraviolet light Provides additional benefits of correction for Ultraviolet (UV) light which can register on film and video as a bluish cast and can obscure distant details Can be left on the lens at all times and is double threaded to stack additional filters such as: ND, Polarizer, etc