Spectra Premium GM37C Fuel Tank for Chevrolet BelAir/Biscayne/Impala Spectra Premium fuel tanks meet or exceed the performance of the original equipment fuel tanks they replace Lock ring included with tank Made with corrosion resistant O.E.M. approved Ni Terne steel All units are 100 percent water based leak tested after full product assembly All units are 100 percentage water based leak tested after full product assembly