About this item SWIVEL BRASS DOT FITTIING: The YiaChuii free 360° swivel DOT air hose fittings are made of high-quality CA360 brass, meets D.O.T. FMVSS 571.106 approved, SAE J1131 air brake system requirements, with corrosion resistance, high-temperature ductility, low permeability and long service life. And 1/2″ NPT threads are pre-applied with sealant to prevent leaks AIR POWER LINE: The semi-truck air line kit’s double-braided design consists of interwoven spirals and is manufactured using a 3-layer integrated molding process. The air line hose assembly has higher burst pressure and better resistance to twisting, with a longer service life Protective Spring: The spring fits tightly into the connector without loosening, the spring surface is plated to prevent corrosion, and the steel spring ensures that the air hose at the connector will not be damaged due to excessive bending and twisting at high speeds Heat-resistant materials: Our semi truck air hose is made of thermoelastic heavy-duty EPDM rubber, which can adapt to extreme temperatures from -40℉ to 200℉, ensuring stable use in extreme environments and all year round Application: Meets or exceeds SAE J1402 – Type A – DOT FMVSS No. 106 – Brake Hoses, 49 CFR 571.106,Replaces: Tectran 13S15401, Tremec Sloan 455180DSET, Philips 11-8115