This specification covers electrical insulating sleeving suitable for use on lead wires and in connections in electrical apparatus, such as motors, transformers, and switch gears. Materials are limited to a flexible tubular product made from a woven textile fiber base, such as cotton, rayon, nylon, or glass, thereafter impregnated, or coated, or impregnated and coated, with a suitable insulating material. Sleeving is categorized by the type of coating, base fabric material, dielectric breakdown voltage, temperature index, minimum wall thickness, and inside diameter. According to type of coating and base fabric material, the sleeving is classified into seven types: Type I, Type II, Type III, Type IV, Type V, Type VI, Type VII. On the other hand, the sleeving is classified into four grades according to its minimum average dielectric breakdown voltage: Grade A, Grade B, Grade C, and Grade C-2. Different tests shall be performed in order to determine the following physical properties of sleeving: dimensions, color, defect, flammability, push-back resistance after heat aging, and flexibility after heat aging.