The bowel is smooth ,and it can be bended or rolled, bearing abrasion, with a low wind resistance and a light weight and it can bear a high temperature of 250℃. It is suitable for transp ortation of hot air and is used in industrial mechanical equipments such as drying equipment, dehumidifying equipment,UV machine, car engine, and etc. Pipe diameter specification is between 19 mm~305 mm,with a determined length of 4 meters and the temperature can reach as low as -70℃.