Proflows 450 Series hose is constructed from a chlorinated polyethylene (CPE) synthetic liner, wrapped in a lightweight nylon outer shield. It is resistant to hydrocarbon based fuels so it can be used in fuel systems using E10, E85, diesel, methanol and all premium unleaded fuels. Its nylon outer cover provides greater flexibility over our traditional 100 Series hose, while still retaining great operating pressures. To be used with 100 and 500 Series fittings. Note: Not recommended for transmission lines or near high heat environments. This hose is not designed for use on high pressure power steering transmission, brake and high pressure hydraulic applications. A support spring may be needed in a vacuum application with tight bend radii.