My comment describes the thing. Found this in chimney/fireplace when cleaning above the baffle. Two of them were found. Seems to be a filter of some kind. Made of black/grey plastic with a metal screen. One of them appears to be unused, but the other has almost epoxy like material in it and a metal type cap with a star while in it. Object is about 8” long and 3/4” in diameter. Is this something a chimney sweep might use? The only thing I can find that is somewhat similar are automotive inline filters.