Listings state the inside diameter, the length and the working pressure. A hose that is the right diameter but the wrong material will fail early: fuel injection hose and carburettor hose are rated differently, and using the low-pressure type on an injected system is a fire risk.
Metal lines are sold pre-bent for a specific route and as straight lengths. Pre-bent lines save time and avoid kinks; straight lines require a flaring tool and the correct fittings.
Hoses that carry fuel or vapour must be rated for the fuel type. Ethanol blends attack some older hose compounds from the inside.
