Balboa P/N 58132 Auxiliary Heater 5.5 kW. This auxiliary heater is plumbed in series after the main spa pack heater and adds 5.5 kW of additional heating power, which typically doubles the heating power and reduces the heating time to 1/2. Requires 240 volts 60hz 30 Amp 2-pole service that has GFCI protection. It is delivered with a control cable that connects across the main spa packs heater connection circuit board terminals and thus acts as a slave heater which is enegized when the main spa pack’s heater is energized. Overheat interlock is provided. UL Listed USA and Canada. Your #1 Hot Tub Parts Replacement store! This item is in the category “Home & Garden\Yard, Garden & Outdoor Living\Pools & Spas\Spas & Hot Tubs”. The seller is “hot-tub-parts” and is located in this country: CA. This item can be shipped to United States, Canada.