13.3 mil. Black cotton cloth with non-corrosive rubber resin adhesive. Hand-tearable, extremely conformable, highly resistant to humidity and galvanic corrosion. Holds tightly on rough and irregular surfaces. Adhesive will not dry out. Used for insulation and to protect industrial harnesses and electrical wires from physical damage caused by friction, for over wrapping low voltage splices and general electrical maintenance jobs. Dielectric Strength: 1kV. Insulation Class: 176 deg * F Tensile Strength: 46 lbs/in. Elongation: 4%. Meets ASTM 4514-85. Individually cello-wrapped (no label) - 10 rolls per tube sleeve. 1 ^ 1 /2^ prime prime (38.1mm) neutral core.