News flash!!! The 58028 has been replaced by the 53349 heater. Complete replacement assembly for Jacuzzi systems. If your board has software version R-574, then the replacement is the 53349
For Jacuzzi R-576, and ALL Balboa LE, and Value systems that are Non-M7 (they have a single temperature sensor), then select 58019.
Specs:
58028 - 4 KW, 1 PSI set Pressure Switch.
58019 - 5.5 KW, 2 PSI set Pressure Switch.
58025 - 5.5 Kw , 2 PSI set pressure switch and 2X1.5 inch heater union tailpiece. (for replacement you can order the 58019 because you wont need the tail piece )