Balboa VS510SZ 5.5kw Spa Pak 54371-03 is the previous version of the VS510SZ spa pack with case, circuit board and heater.
New model released now has a 4kW heater and is VS510SZ - see G4154
VS501 Control System Bundle VS501 5.5kw Spa Pak with Mini Oval Topside 54220-Z Balboa Water Group VS501Z Control System Features:115/230v Pump 1 circuit115/230v Blower circuit115/230v Ozone...