This part of IEC 60684 gives the requirements for four types of heat-shrinkable, flame retarded, fluid resistant, elastomer sleevings, nominal shrink ratio of 2:1. Type A: standard wall thickness for use at temperatures up to 120 °C Type B: thin wall thickness for use at temperatures up to 120 °C Type C: standard wall thickness for use at temperatures up to 150 °C Type D: thin wall thickness for use at temperatures up to 150 °C These sleevings are normally supplied with internal diameters up to 102 mm for the standard wall thickness and up to 51 mm for the thin wall thickness. The standard colour is black. Sizes or colours other than those specifically listed in this standard may be available as custom items. These items are considered to comply with this standard if they comply with the property requirements listed in Tables 1, 2, 3, 4, 5 and 6 except for dimensions and mass. 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.