Vintage 32mm slip-on filter. As the photos show, it can be disassembled and the internal glass replaced with something else. You can also use it with colored filters, expanding its range of uses. I believe this is a rather rare item. The glass has some chipping around the edges (which won't be visible when installed). The glass itself seems to be of high quality. I've also included photos of the hairline scratches and two spots of what looks like mold or dirt. It still functions perfectly well as a protective filter as is, but it would be a great item for someone who enjoys experimenting with different types of glass. The screw threads are precise and there are no snags.