3-Way Fsk Backing with Aggressive Acrylic Adhesive and Protected by Kraft Paper Silicone Release Liner Alum Foil Tape. Aggressive Acrylic Adhesive: Provides excellent peel adhesion and permanent bonding for secure sealing. HVAC Ductwork Application: Specially designed for sealing insulation joints and seams against moisture and vapor. 3-Way FSK Backing: Features foil-scrim-kraft structure matched with kraft paper silicone release liner. Waterproof Performance: Ensures effective waterproofing and protection for insulation systems. Flexible Customization: Supports full customization, minor customization, and customization from samples or designs. ISO Certified Manufacturer: Produced by a factory with ISO9001:2015 and ISO14001 certifications since 1997. Professional Grade Quality: Super performance tape with high tensile strength and initial tack for professional use.