Here is a Standard 4 KW Flo Thru Spa Heater Element, a great choice for Gecko, Spa Builders, HydroQuip and many others. A awesome price and fast shipping too.
Tech Note: For Balboa, we recommend replacing with the Bent Style 4 KW Element, Part # 25404BI, the bend will allow for Sensor clearance, very important. As always, feel free to contact us with any questions about this element or your spa.