3M 3380 Silver Aluminum Foil Tape, 0.75" width x 5yd length (1 roll) General purpose foil tape. Applies to both fibrous and sheet metal ducts and conforms to irregular surface. US Coast Gurad approve for interior finishes. Acrylic adhesive supplies superior temperature, U.V. and solvent resistance. The foil also serves as an excellent barrier against moisture, dust, flame, and certain chemicals. Thermal conducting; heat sheilding; light reflecting; and moisture barrier.