I think some were filtered and others not, and the filtered were the 9 mm (most used in Europe). Some pipes on discount are 9 mm because they are a little harder to sell in the U.S. But the billiard with the band and maybe others were non-filtered, which is what I would have preferred. Of course, you can buy adaptors to replace the 9 mm filters, or smoke them with or without the filter depending on your preference, or switch off at will. I think, for new pipe smokers, filters are one of the most confusing issues. It takes a little learning to know about the various kinds, and which brands or series are unfiltered, no deep mystery but requiring attention.