3M Scotch® Fire-Retardant Electric Arc Proofing Tape #77 is a specialized and critical safety expendable in the film and stage industry, designed to protect electrical cables from the intense heat and flames generated by fault arcs from nearby cable failures. This premium-grade, 30 mil thick, flame-retardant tape is specifically engineered with an intumescent elastomer backing that expands to form a thick insulating charred buildup when exposed to high temperatures, creating a firewall that shields vulnerable cables.