Compatible with 2007-2010 Mini Cooper 1.6L L4 DOHC and 2009-2010 Mini Cooper 1.6L L4 SOHC. Part Numbers: Upstream Oxygen Sensor: 234-5135, 2345135; Downstream Oxygen Sensor: 234-4488, 2344488. Oxygen sensors are important components of fuel and emission systems. They measure unburned oxygen in the exhaust, effectively detecting oxygen content in the gas and sending data to the engine computer to help optimize fuel economy. Designed for easy installation with a precise fit based on vehicle data. Upstream sensor has 6 pins, downstream sensor has 4 pins. Plug-and-play design allows direct replacement without modifications, saving time and effort. Material: ABS Color: Black Package Contents: 2 x Oxygen Sensors Note: Other items not included. Due to lighting effects and monitor settings, the actual color may vary slightly from the image. Measurement error allowed within +/- 1-3 cm.