This two in one filter features both a Circular Polarizer to help remove reflections and glare from non-metallic surfaces, and a solid Neutral Density filter to help capture longer exposures. The multicoated CPL + ND filter features anti-reflection and anti-color cast properties, and conveniently fits in the dedicated drop-in slot of the M7 filter holder with an independent rotation wheel that allows you to adjust the polarization of the filter.