The Elring Fuel Injector O-Ring - 455830 is a small, circular rubber ring that is used to seal the connection between a fuel injector and the fuel rail. This o-ring helps to prevent fuel leaks and maintain proper fuel pressure within the fuel system. It is made of high-quality materials and is designed to withstand the harsh conditions of the engine compartment. This product is essential for ensuring the efficient and reliable operation of the fuel injection system in a vehicle.