The Formatt Clear Filter is a clear (colourless) filter for colour and black and white films. It also serves as permanent protection for the lens., , , - Each filter is manufactured from Schott-Desag B270 Crown optical glass, , - Absolute consistency of colour and density according to Kodak Wratten standards, , - Precision polishing and grinding achieve unbeatable optical flatness, allowing use even on very long focal length lenses, , - Filter edges are protected by a unique frame for maximum protection and easy handling