This is a storage item that came out while cleaning the storage shed. This is a Canon 58mm circular polarizing filter PL-C. Function: Controls harmful reflected light that interferes with the depiction of the subject, enhancing the photographic effect. Application: Used to eliminate reflections from glass surfaces and water surfaces, or to emphasize the blueness of the sky. Type: A circular type that can be easily used without affecting AF or metering systems. Part number: CZ6-0889. Made in Japan.