These 6' fiberglass chimney brush rods are 440 diameter, 318 fitting.
ACS has been the industry standard for modifying glazed creosote since 1982. ACS attacks dangerous creosote and soot, helps prevent chimney fires, and makes the chimney easier to clean.
Humdinger is used to remove any size flue tile liner in 30 to 60 minutes. Field tested more than 20 years.