The Formatt 5.65 x 5.65" UV 2A Haze Optical Filter made from Schott-Desag B270 crown glass is a wise investment. It can help protect your valuable investment from dust, moisture and scratches, which can lead to costly repairs.nnIt provides virtually 100% UV absorption. The Haze 2A filter is excellent for conditions where UV is very present, such as at high altitude.nn- If desired, it can be left on the lens permanently for continuous protectionnn- Haze filters offer additional correction benefits for ultraviolet (UV) light which can register on film and videotape as a bluish cast and can obscure distant detailsnn- Ultraviolet filters allow you to correct for UV effect to varying degrees