Pro-Air Duct Sealant UL 181 AM-BM Listed - Pro-Air Duct Sealant UL 181 AM-BM Listed is non-hardeningPro-Air Duct Sealant UL 181 AM-BM Listed 1 Gallon Pail features include:Water-based fiber-reinforced duct sealant/mastic formulated for indoor/outdoor useUse on metal heating, ventilating, and A/C duct systems; as well as fiberglass duct board systems and flex duct systemsRecommended for use to 10" of water column pressure without the need for fiberglass mesh reinforcementBelow is more info on our Pro-Air Duct Sealant UL 181 AM-BM Listed: