Spectra Premium Spectra Fuel Tank TO31E Unit is designed to OE fit, form and function requirements accomplished by leveraging our OE fuel system design expertise Lock ring included with each tank to reduce installation time and to ensure a complete repair Made with corrosion resistant, OE approved, Ni Terne steel for durability Unit is leak tested after production to ensure product in free from fuel and / or evaporative leaks Each new fuel tank is road tested to ensure real world performance and to verify that each design meets our high standards for quality