IEC 60684-3-247:2011 gives the requirements for two types of heat-shrinkable, polyolefin sleeving, dual wall, not flame retarded with a nominal shrink ratio of 3:1. This sleeving has been found suitable for use at temperatures of up to 100 °C. - Type A: Medium wall, internal diameter up to 200,0 mm typically; and Type B: Thick wall, internal diameter up to 200,0 mm typically.