Genuine vintage Minolta wide-angle 55mm circular polarizing filter. Rear threads are 55mm, there are no front threads and the front is about 65mm wide with light-trap grooves to prevent flare. You cannot stack another filter on the front. If you are not familiar with this filter design, it is for use with wide-angle lenses to prevent vignette. These filters are not easy to find. This one is in excellent condition, very clean glass without any marks, with a few tiny nicks on the rear threads (check photos) but otherwise pristine. Photos are of the actual item and it comes exactly as pictured in a somewhat worn Minolta filter protector. I will combine shipping. [2040,L-02]