Summary: It's round!
Comment: OK, It's a UV filter. I use it mainly as a piece of "clear" glass to protect the front element of a lens. What can you say about this one? It is round. The mounting is solid and a nice black color with legible lettering. The threads are accurately cut and it easiy screws in and out without getting stuck or coming loose. The middle part is transparent so you can take pictures through it. It looks to be of a uniform density, with neither darker nor lighter areas. All in all, it is everything anyone could ever want in a UV filter. The single negative thing I saw was that it is inexpensive. If you get a charge of telling everyone how expensive your camera and ancillary equipment are, forget this filter.