If your Nissan's air conditioning is blowing warm air and you hear a clicking noise or the compressor clutch isn't engaging, this replacement clutch assembly might be the fix. It's specifically for the 2007-2012 Nissan Altima and Sentra with the 2.5L engine. This is for the DCS171C compressor model, which has a 6-groove pulley and 127mm diameter. It comes prefilled with 180ml of PAG 46 oil, compatible with R134a refrigerant. It matches a long list of OEM part numbers (like 1010886, 638784, etc. – check the full list). IMPORTANT NOTE: If your old compressor failed internally (seized or sent debris through the system), you likely need a whole new compressor and a full system flush. This clutch is for when just the magnetic clutch coil or bearing has failed. Consult a mechanic if you're unsure. Comes with a 1-year guarantee.