3M Heavy Duty Aluminum Foil Tape 438 is a high-performance foil tape designed for numerous applications across a broad range of industries. Comprised of a dead soft aluminum foil backing with a highly engineered pressure sensitive acrylic adhesive, it is ideal for heat shielding, heat reflecting, seaming and sealing.Withstands Exposure to High Heat and Humidity Consisting of a dead soft, thermally conductive aluminum backing, 3M Heavy Duty Aluminum Foil Tape 438 dissipates heat over the surface of the tape to reduce hot spots and protect the substrate from the effects of high temperatures. Coated with our highly engineered acrylic adhesive, it is capable of withstanding exposure to high heat and humidity while maintaining a strong and reliable bond. This tape can withstand a variety of moisture, weathering, UV and solvents in order to provide an excellent work life, indoors or out. 3M Aluminum Foil Tape 438 is UL Recognized to UL 746C (File E 122798) and Classified by UL to UL 723 "L" for low flammability rating (File R 7311). It meets F.A.R 25.853(a). Temperature use range is from -65° to 300°F (-54° to 149°C). Recommended Applications • Heat shielding of delicate parts • Heat reflecting • Moisture barrier • Seaming and sealing • Refrigerator and freezer coil attachment • Plastic protection against heat and UV exposure