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.nn- Each filter is manufactured from Schott-Desag B270 Crown optical glassnn- Absolute consistency in terms of colour and density according to Kodak Wratten standardsnn- Precision polishing and grinding achieve unbeatable optical flatness, enabling use even on very long focal length lenses.nn- The filter edges are protected by a unique frame for maximum protection and easy handling