33-0033A HydroQuip | Circuit Board, HydroQuip (Balboa), VS511SZ, Serial Standard, 4220/6220B $300.88 Board Model - VS511SZ
33-0032C HydroQuip | Circuit Board, HydroQuip (Balboa), VS511Z, 4220/6220B, Mini/Duplex $300.88 Board Model - VS511Z