Featuring aggressive acrylic adhesive, aluminum foil backs these tapes, providing thermal conductivity for heating and cooling efficiency. These tapes also create a water proofing barrier and air leak protection. All aluminum foil tapes are 2" wide and 60 yards long. They are sold in cases of 1, 6, or 24, depending on the type. These three types of aluminum tapes offer thicknesses of 5 mil, 3.1 mil, and 4.6 mil. Choose this type of tape for long service life, indoor/outdoor use, and strong adhesion for difficult to adhere surfaces.