21.100 in.Lg, 2.000 in.Id;
An item composed of one or more materials, molded, compressed, and/or baked into a rigid covering of irregular shapes and sizes. it is designed to cover air ducts and/or air duct fittings used in air conditioning, heating, cooling, pressurizing and de-icing systems to restrict the dissipation of heat. it may completely or partially encase the item for which designed. it may be furnished with or without fillers, cement, and/or separate or attached accessories for installation, (excluding flexible air duct covering and rigid pipe and pipe fitting coverings used in construction and building materials). Excludes insulation blanket, thermal, aircraft; insulation pipe fitting covering, thermal; and insulation sleeving, thermal.
Classification: Other parts of airplanes or helicopters for use in military aircraft (excludes propellers, rotors, undercarriages, and parts thereof)
NSN 5945-00-089-0733
NSN 5950-01-468-5431
NSN 6320-00-578-6898
NSN 6135-01-136-8306
NSN 6685-01-177-4870
NSN 5920-01-656-3089
NSN 6135-01-203-9977
NSN 5945-01-151-9235
NSN 2925-01-528-7333
NSN 5910-00-950-8219
NSN 5960-01-080-3117
NSN 5950-01-620-6718