Nashua 1.89"x50 YD Silver Foil Tape, a 2 mil foil with a rubber-based adhesive system, is suitable for both interior and exterior use. This tape is ideal for taping joints and seams against moisture and vapor on foil jacketed insulation and is commonly used in the automotive industry for general repairs. Its dead soft aluminum foil backing ensures extreme conformability to irregular surfaces, making it easy to use and highly effective.