Cokin PURE Harmonie filters are the thinnest and the lightest in the world. With a thickness of 3.3mm for the Multi-Coated Anti-UV (UV MC), they are almost invisible when mounted on your lens. Their weight is so light that you won't even notice that they are attached. Cokin PURE Harmonie filters have been engineered with no compromise: very robust, compatible with all lens caps and multi-coated with EVERCLEAR 5 Coating Technology to withstand almost any conditions. Super lightweight for maximum AF performance and ultra-shallow profile to prevent vignetting, they are just perfect. They are PURE. Anti-UV filters are used to prevent ultraviolet light from getting through the lens, by reducing haziness or fogginess caused by that type of light. Anti-UV filters offer a physical protection from dust or scratches to the lens. PURE Harmonie UV MC filters are made of extremely resistant glass with very high level of light transmission. Thanks to their extreme thinness, PURE Harmonie UV MC filters also prevent from lens flare that could occur when using traditional UV filters.