Opteka 27mm High Definition II UV (0) Ultra Violet Haze Multi-Coated Glass Filter High-index / low-dispersion optical glass with HD2 Technology Multi-Coated and heat treated glass to eliminate distortion and minimize light reflections Pictures gain brilliance and disturbing blue casts are avoided Designed to maximize day and night shots by providing maximum light and image transmission Penetrates haze, adds warmth, and protects your valuable lens from scratches, dirt, fingerprints, etc.