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
Gecko S-Class Spa Pak 0202-205212. Operates a single pump, circ pump, ozonator, LS and includes 4kW heater. With J&J connections (does not include receptacles). Dual voltage - S-Class Spa...