CCWI-181 is a versatile, all purpose duct sealant for use on all types of metal duct, glass fiber duct board and flex duct, as well as duct fabric and flexible tubing runouts. CCWI-181 incorporates a built-in polyester reinforcement for exceptional strength, with UV inhibitors for outdoor use. CCWI-181 is UL 181A-M and UL181B-M Listed Passes ASTM C-731, D-2202 USDA, EPA and FDA Approved, LEED compliant SCAQMD Rule 1168.