Including plug-in filter holder (drop-in holder) 52mm Compatible lenses: EF 400mm F2.8 IS III USM, EF 600mm F4L IS III USM Filters the polarized light of non-metallic surfaces, reducing reflections. Increases Saturation and Contrast Reduces haze in distant landscapes for richer, more vivid colors. Strongest effect when used at an angle of 90 ° to the sun.