37MM JAPAN OPTICS Circular Polarizer (CPL) Slim-Frame Filter Made with JAPAN OPTICS. SLIM FRAME FILTER - Perfect For Wide Angle Lenses ELIMINATE REFLECTION: Removes unwanted reflections from non-metalic surfaces such as water and glass - DARKENS THE SKY: Creates dramatic sky/cloud contrast. COLOR SATURATION: Saturates colors without changing color balance. PROTECTIVE CASE: It is stored in a protective case, which protects the filter extends its lifetime considerably.