Duct and Insulation Tapes 600 Series   –  Premium grade, dead soft, aluminum foil   –  Premium grade; waterproof, printed polycoated cloth; UL 181B-FX adhesive system. Designed for HVAC flex duct applications, installing air ducts, air connectors; making connections and splices; resists flame spread, smoke generation, mold growth, humidity and high temperatures. Meets Specs: UL 723; UL 181B-FX, Flame Spread lndex-15, Smoke Development lndex-30.   –  Carolina Tape   –