Fan blade retainer nut. A solid metal or plastic block with a threaded hole in the center which is used to tighten or adjust the Air Conditioning Condenser Fan Blade. Engine Cooling Fan Blade Nut. Housing or Panels that surround the Cooling Fan to direct Air. retainer. Air Conditioning (A/C) Condenser. Engine Cooling Shroud. Motor. Shroud clip. Included with: Electric Cooling Fan, Fan assembly.