Premium Flo-Thru Heater Element 5.5 KW - Center TerminalPremium Hot Tub Heater Element 12 0500 K The Flo Thru Heater element is the most common style on the market. The low profile design and precision American manufacturing makes this heater element easier to replace and more durable than other lesser brands. It is designed to be used as a replacement in most Balboa, Gecko, Hydro Quip and almost any other brand of flo thru heater assemblies that have center terminal elements. Description: Low Profile