Polyken/Nashua 438X Extreme Weather FSK Tape is a Foil, Scrim, Kraft laminate tape with acrylic adhesive suitable for use in a wide range of temperatures. Used to seal and patch FSK duct boards and insulation. Provides an extra-strength seal to maintain vapor barrier integrity. Polyken/Nashua 438X is specially designed to meet high strength, tear resistant sealing tape requirements. Provides excellent adhesion to substrates over extreme temperature ranges (from -35°F to 260°F). Diamond pattern matches most FSK boards and blankets. 438X is UV, moisture and mold resistant and is non-solvent for less odor. It also has low VOC content and contributes toward satisfying EQ Credit 4.1 (Low Emitting Materials, Adhesives & Sealants) under LEED®. Meets flammability requirements for use in construction, aerospace and marine applications. Comes on a paper release liner.