The Ingersoll Rand 39201884 pressure switch is an OEM part most commonly asociated with 3HP, 5HP and 10HP rotary screw compressors manufactured by Ingersoll Rand between 1992 and 1995. Typically these models had ESP in the model number. The serial numbers most commonly start with AO. There were several different models during this time frame that took different separator kits. Please contact our parts department for confirmation this will work with your air compressor.