Please Note: Be sure to clean the air conditioning system before installation, otherwise it will cause compression broken. This compressor is a single hole plug. Please make sure the plug is the same as your old one. Please make sure the installation site is clean. Or, it will cause operating obstruction, even make the temperature of the compressor very high, and the belt on the clutch may melt. Because the item is with oil when sent to you, so there is no need to add oil when you use it the first time. But you need to add the refrigerant , please add about 500g, don't need to fill up. There may be noise if the refrigerant is added too much. .