15 mil (0.38mm) Friction Tape - Black Cotton with non-corrosive Rubber Resin Adhesive. Its cloth backing makes this tape easily hand-tearable and extremely conformable. Highly resistant to humidity and galvanic corrosion. Holds tightly on rough and irregular surfaces, its adhesive system 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 strenght: 1,000 V. Insulation class: 176ºF. Tensile strength: 42 lbs/in. Elongation: 8%. Meets ASTM 4514-85. Individually cello-wrapped (no label) - 10 rolls per tube sleeve. 1 1/2" (38 mm) neutral core.

Mill:

• A "mil" is a unit of thickness equal to one thousandth of an inch. 
• To convert mil to inches take mil & divide by 1000. 
• Thus, a 2 mil bag would be .002 inches thick.
• Example: Ex: 2 mil/1000 =.002 inches