Airseal 22 is a UL 181 A-M & B-M listed fast drying water based duct sealant with excellent adhesion, formulated to pressure seal all types of HVAC duct systems, including sheet metal, fiberglass duct board and all flexible duct.Features: LEED EQ Credit 4.1 Cures to a tough, flexible film Formulated Indoor and Outdoor use Seals High Pressure HVAC Duct Systems Exceeds all SMACNA Pressure and Sealing Classes Has excellent mold and mildew resistance