1Applicable Model: Control valve is fit for Q7 3.6L 4.2L 2007?2010, fit for R8 All Models 2008?2012, fit for RS4 All Models 2007?2008, fit for S4 All Models 2004?2009, etc. 2Part Number: Ac compressor control valve replace part number is ECV15 for reference. Please double check the part number of your item to ensure perfect fit. 3Accurate Control: Control valve adopts advanced electronic control technology, which enables high precision control, thus improving the air conditioning effect of the vehicle. 4Practical Parts: Control valve is to regulate the car air conditioning system cooling, heating components, it is controlled by electromagnetic force solenoid valve automatically open and close to change the compressor air flow. 5Stable Driving: Reliable control makes your vehicle more energy efficient and environmentally friendly, while improving driving efficiency and making your driving experience more comfortable.