Scotch Tape 77W is a 30 mil THK, premium-grade, flame-retardant, electric arc proofing tape. This tape is 600 V rated and is suitable to protect most types of electrical cables when exposed to potential failures in an adjacent cable. It is designed with a flexible unsupported elastomer, which makes it easy-to-apply and easy-to-remove for cable inspection. Intumescent elastomer backing Tape measures 3 in x 20 ft x 30 mil for protecting most types of electrical cables when exposed to potential failures in an adjacent cable Conformability offers virtually wrinkle-free wrapping with minimal effort UL Listed and RoHS 2011/65/EU Compliant 10 rolls/case.