-an all purpose, fiber-free, duct sealant for use on all types of metal duct, fiberglass duct board, flex duct and duct fabric. Distinguished by its ability to accomodate minor vibration and movement, Flex-Grip 550 stays flexible and will not crack. Flex-Grip’s excellent coverage rates and brush-on application reduce the amount of sealant used and lower the labor cost of the installation.
