This specification applies to two types of flexible, crosslinked (Type II) and noncrosslinked (Type I) poly(vinyl chloride) heat-shrinkable tubing for electrical insulating purposes. It is supplied in an expanded form and will shrink to its extruded diameter when heated. Besides dimensional requirements such as inside diameter and wall thickness, the tubing shall also adhere to the following chemical and physical property requirements: restricted shrinkage; longitudinal change; dielectric strength; color and color stability; water absorption; specific gravity; volume resistivity; flammability; heat shock; low-temperature flexibility; tensile strength; elongation; heat resistance; resistance to fluids such as hydraulic fluid, JP-4 fuel, lubricating oils, de-icing fluid, and NaCl solution; copper corrosion; behavior during copper dust humidity test; and shelf life.