3M™ Aluminum Foil Tape 3380, 2 mil aluminum foil, 1.5 mils acrylic adhesive, 40 lb polycoated natural kraft paper, (Venture 1520CW)UL 723 listed. US Coast Guard approved for interior finishes. The foil serves as an excellent barrier against moisture, dust, flame, and certain chemicals. Acrylic adhesive supplies superior temperature, U.V. and solvent resistance.