3M Venture Tape UL181B-FX Mastik Foil Tape 1580-P is a UL printed aluminum foil tape that provides an instant water-resistant bond on most surfaces, including sheet metal, duct board, flex duct board, and duct wrap vapor barriers. Designed for superior performance, this conformable 2-mil aluminum foil has a heavy coating of mastic adhesive that applies easily to fibrous, conformable and sheet metal ducts. This tape is also hand tearable and conforms to irregular surfaces for easy installation. Ideal for applications requiring water-resistant bonding, this 3-in, UL181B-FX listed tape offers reliability over a wide range of environmental conditions, including humidity. Achieve a durable, water-resistant bond on your duct surface with 3M Venture Tape UL181B-FX Mastik Foil Tape 1580-P.Applies easily to fibrous, flexible, and sheet metal ducts, and conforms to irregular surfaces