Circular Polarizer Filter, 2.5x Filter Factor, +1.3 Stop, Helps to Eliminate Reflections and Glare, Reduces Haze in Landscapes, Greater Color and Tonal Saturation, Optical Glass Construction, Multi-Coated, Aluminum-Alloy Filter Ring, Thin, Aluminum-Alloy Filter Ring, Plastic Case The Haida 52mm Slim Pro II Circular Polarizer Filter helps to reduce reflections and glare by filtering out light that has become polarized due to reflection from a non-metallic surface. The light from the sun naturally becomes partially polarized due to reflecting off electrons in air molecules causing the light to scatter into what appears as haze. A polarizing filter arranges and filters this directionally polarized light perpendicularly to the reflected light allowing for the absorption of much of this light.