The Formatt 4 x 4" Linear Polarising Filter allows you to achieve an optical performance level hitherto unmatched. The polarising film is manufactured between two pieces of Formatt's crystal-clear white optical glass. The absolute clarity of the glass combined with advanced polarising material makes Crown polarising filters particularly effective in demanding scenes. Formatt filters are available in a complete range of colour graduates, effects, corrections, neutral density and black-and-white filtration. Formatt, a company with three generations of experience in manufacturing professional filters, produces every filter to the highest technical standards. The finest materials, combined with state-of-the-art production technology, have achieved a level of optical excellence unmatched elsewhere. Polarisuers are ideal for photographing in water or through glass - Reduce unwanted reflections and glare - Saturate colours - Intensify blue skies - Enhance contrast - Penetrate haze - Manufactured in Schott-Desag B270 Crown optical glass - Absolute colour and density consistency to Kodak Wratten standards - Precision grinding and polishing achieves 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