A 30mil low voltage rubber splicing tape made of high quality, un-vulcanized rubber, which is suitable as a primary insulation for splices in electrical wires and cables of not more than 600 volts, which are normally over wrapped with Electro #45 Friction Tape or Vinyl Tape. Superior insulating & bonding qualities make it an excellent choice. Black with blue liner, 30 mil thick, 275psi tensile strength, 500% elongation, 490 volts per mil dielectric strength. Meets requirements of ASTM-D-119 and HH-I-553C, Grade B, UL510 Listing #2C58. 50 rolls/case.