? Part Number: 58104 ? Manufacturer: Balboa ? Material: Metal ? 4 kW ? 240 volts The Balboa Heater M7 VS with Studs 4Kw ? 58104 is an innovative pool heater that incorporates some of the newest technology available. The 58104 replacement heater is powerful with a 4kW heater and 240 volts. The Balboa 58104 has 2-inch unions that allow you to attach it to the spa?s plumbing, and the 58104 heater is compatible with a wide assortment of parts. You will also notice the power and efficiency of the M7 technology that is used in the Balboa heater, which is some of the most innovative technology on the market.