High quality unvulcanized rubber that will bond quickly to itself to form a solid mass of watertight protection. Self fusing with liner. Can be used as primary insulation for electrical wires and cable splices up to 600V. Conforms to irregular shapes and is flexible to withstand expansion and contraction. Highly resistant to salt water, steam, oils, detergents and other chemicals. Dielectric strength 490 volts per mil.