A rigid or flexible item composed of one or more materials, having uniform inside and outside diameters in the entire length. It may be furnished in segments or split-round or full-round sections, composed of one or more layers. It is specifically designed to cover pipe, tubing, and like surfaces, to restrict the transfer of heat from the high temperature surface to the low temperature surface. It may also include protective coatings, jackets, attaching cement, attaching bands, and/or accessories, (excluding prefabricated components used in aircraft applications). excludes insulation pipe covering, thermal, aircraft.