These sheets of 60684-3 give the requirements for three type of non-heat-shrinkable sleeving, extruded from PTFE. Sleeving of this type is normally available with internal diameters up to 8,53 mm and in a range of wall thicknesses between 0,15 and 0,51 mm. This specification covers three levels of wall thickness: "thin wall", "standard wall" and "thick wall" related to nominal internal diameter and with corresponding differences in requirements for breakdown voltage. Experience of product performance indicates that PTFE sleeving may be suitable for inclusion in systems for operation at temperatures up to 250 °C. These sleevings are normally available in the following opaque colours: black, brown, red, orange, yellow, green, blue, violet, grey, white, pink and turquoise. It is also available as non-coloured. Sizes or colours 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 other property requirements listed in tables 1 and 2.