These sheets of IEC 60684-3 give the requirements for heat-shrinkable (low and high shrink ratio) polytetraflourethylene (PTFE) sleeving. It is normally available in expanded internal diameter sizes up to 12mm in three wall thickness ranges as supplied in the low shrink ratio (sheet 240, 241 and 242) and up to 100mm in one wall thickness range as supplied in the high shrink ratio (sheet 243). It is normally available in transparent milk white to light tan in colour and minimum recovery temperature is 350 °C. The procedures described in IEC 60216-1 for evaluation of thermal endurance are not readily applicabl to PTFE: however, experience of product performance indicates that this sleeving may be suitable for inclusion in systems for operation at temperatures up to 250 °C. Sizes other than those specifically listed in this standard may be available as custom items. These items shall be considered to comply with this standard if they comply with the property requirements listed in tables 3 and 4. 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 the application and not based on the specification alone.