Jacuzzi Whirlpool [7.0A] [1S] OEM J Pump Bath Pump (HB21000) aosmith The FC 0133M and PSG40N P4 M compatibility The FC 0133M and PSG40N P4 M compatibility give this part practical value because cartridge filters work best when the replacement matches the intended housing and service application closely A good weir is important because it can improve surface cleaning action and help floating debris move more effectively toward the skimmer basket Bath pumps are one of the most important replacement components in a whirlpool system because they create the water movement that defines the overall bathing experience Helps restore core water movement in compatible whirlpool bath systems