These filters are in usable condition, and I have tested that each filter's front and rear threads screw into another filter without difficulty. I have not cleaned these filters, and they generally show some usage; some are mint and spotless but most have some dust, many have e.g. some scuffing and wear on the paint, however I will not sell a filter with obvious meaningful damage (see photos for a representative idea). They will be fine to use for appropriate applications after you clean them. The photos are of the stack at the time of listing, and as I sell and/or add more filters there will be filters not pictured and vice versa. They will have various weights and differing thicknesses.
Most of the filters in this listing are vintage 1970s-1990s but occasionally there will be a modern one, some with fantastic coatings that reflect almost no light, however please assume you'll get a vintage one with vintage coatings; the Hoya glass and coatings were among the best available at that time and they do a good job of reducing reflections (Hoya is a giant in the optical glass and coatings industry and made filters for many, many companies including prestige brands). Again, please feel free to message me with any specific requests.
Satisfaction guaranteed. My goal here is what I view as a win-win: I'm offering these at a price that doesn't even really pay for my time, but I really would like these useful items to become useful again, as a kind of pushback against the cycle of excessive consumerism. You can get better modern filters for sure, but these are more than adequate for almost all purposes — I use filters like this myself to make many photos, for example. If you're not delighted with what you get, just let me know.
Look at my other listings for premium Tiffen brand and B+W filters. I also have a listing for generic vintage filters from store brands and the like; ironically these were likely Hoya too, with less expensive coatings.