IEC 60684-3-216 Ed. 2.0 b:2019

IEC 60684-3-216:2019 Gives the requirements for four types of heat-shrinkable, flame-retarded, limited-fire-hazard sleeving with a thermal endurance rating of 105 °C as shown below:
Class A: thin wall, shrink ratio 2:1, internal diameter up to 102,0 mm;
Class B: medium wall, shrink ratio 2:1, internal diameter up to 60,0 mm;
Class C: thick wall, shrink ratio 2:1, internal diameter up to 51,0 mm;
Class D: medium wall, shrink ratio 3:1, internal diameter up to 40,0 mm
Materials which conform to this specification meet established levels of performance. However, the selection of a material by a user for a specific application should be based on the actual requirements necessary for adequate performance in that application and not based on this specification alone.