This part of IEC 60684 gives the requirements for heat-shrinkable, polyolefin sleeving, anti-tracking with a nominal shrink ratio of 3:1. This sleeving has been found suitable for use at temperatures up to 100 °C. Typically: medium wall, internal diameter up to 110 mm. These sleevings are normally supplied in the colours red or brown. Since these types of sleevings cover a significantly large range of sizes and wall thicknesses, Table A.1 in this standard provides guidance on the range of sizes available. The actual size shall be agreed between the user and the supplier. 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. This sleeving is designed to be used in medium voltage cable accessories and as such electrical performance must be proven as part of the assembly. Examples of this are described in HD 629 and IEC 60502 series.