Duct and Insulation Tapes 600 Series – Laminated foil/scrim/kraft (FSK) – Laminated foil/scrim/kraft (FSK); extremely high tack, aggressive rubber-based adhesive; removable liner. Engineered to seam and seal fiberglass duct board and duct wrap to maintain vapor barrier integrity; adheres tightly when smoothed down. Meets Specs: UL 723, Flame Spread lndex-10, Smoke Development lndex-25; ASTM E-84. – Carolina Tape –