A polarizer is different than most filters in that it is composed of two pieces of glass， mounted independently inside a round frame so that one can be rotated relative to the other. As it is rotated， it increasingly cuts out glare and haze. With an SLR， you can actually observe this change through the viewfinder. Polarizers reduce glare from water， glass， or any non-metallic surface. You can also use a polarizer filter to darken blue skies.                                    Features            Lens filter enhances the color and contrast<br>Circular polarizer filters provide color and contrast enhancement<br>The filter could limit the reflection from non-metal surface such as water and glass windows<br>Using the filter. The colors shall become brighter and clearer and the contrast shall be strengthened<br>CPL / circular polarizer filter for camera with a 55mm diameter lens<br>External diameter: 57mm<br>Internal diameter: 55mm<br>Color: Black<br>                                                                                                Package Includes            1 x 55mm Circular Polarizing CPL Camera Lens Filter<br>