Shurtape PC-618 Industrial Grade Duct Tape is a performance grade duct tape which is available in a wide variety of colors. It is used to seal cartons, bind books, repair seats, bundle wires, color code, splice, repair, and seal hatch covers and cargo doors in the shipping, trucking and automotive industries. Shurtape PC 618 Duct Tape can also be used as a condensation barrier in appliance assemblies and for HVAC metal and flex duct sealing. It has a waterproof backing; has excellent conformability and tack; is easy to unwind and tear; and has excellent holding power. UL 723 listed. PC 618 SIL refers to this tape in a silver color and PC 618 CLR refers to the other 11 stock colors which include: black, brown, red, yellow, olive drab, white, orange, green, blue, burgundy and beige (tan). Also please note Shurtape's version of olive drab is very dark as displayed in the product photo. PC 618 silver comes with Shurtape's Polyblended CO-EX technology with is a co-extrusion process which melds polyethylene, cloth and adhesive in a single, high-temperature step which results in a permanent, airtight bond (creates added strength which will not delaminate).