ZIMFLEX brake duct hose is silicone coated, fiberglass fabric hose reinforced with a spring steel wire spiral and external filament fiberglass cord. This hose is use for high temperature purposes. It can endure exposure to high temperatures much better than most other materials and handle temperatures that reach as high as 536°F. This is a must-have feature for industries like plastics processing because they need to channel extremely hot air into an area in order to mold their plastic materials.