Heat shrinkable sleeving is intended for use as a snug-fitting electrical insulator over wire bundles, splices, cables, cable harnesses, bus bars, connectors and terminals, metal or fibrous tubing, hydraulic line couplers, high voltage tubes, flexible wave guides and rectifier leads, as extra insulation over hot spot areas, and as a cable blast shield in rocket launching. Specific property values in section 3 and in the specification sheets should be evaluated for the particular use intended. When a complete moisture proof seal is required, the manufacturer may recommend the use of a suitable sealant at the ends of the sleeving. Heat shrinkable sleeving can be marked before shrinking and be used to identify materials that cannot be marked directly such as unjacketed wire, shielded wire, thermocouple wires, multi conductor cable, asbestos, and fiberglass. Marking shall be in accordance with procedures in mil-m-81531. It should be noted that the wall thickness dimension in the specification sheet or manufacturer's data sheet refers to the sleeving after unrestricted shrinkage; if shrinkage is restricted by the object to be enclosed, wall thickness will be less