Litezupp LR57 series is a form, fit and function replacement for the industry standard 1157 filament bulb that has a BAY15D base and used where there is side facing illumination Dual contacts in the base and offset pins, will replace the 1157 incandescent lamps that go behind a lens of the same color or a clear lens. Non polarized for use in either negative or positive ground systems. Available in Red, Amber and White