This listing is for a set of two oxygen sensors, one for the upstream and one for the downstream of a vehicle's air intake system. The sensors are compatible with Aston Martin, Ford, and Jaguar models and come with four wires each. They are designed to monitor the oxygen levels in the air being fed to the engine, ensuring optimal performance and fuel efficiency. The sensors are easy to install and maintain, providing reliable and accurate readings. Whether you're replacing a worn-out sensor or upgrading your vehicle's air intake system, these oxygen sensors are a great choice. They are a must-have for anyone who wants to keep their engine running smoothly and efficiently. New no box item