Replacement heating element 5.5KW used in Balboa M7 Heaters. It fits all Balboa M7 tubes with 1 or 2 sensors that have the correct curve to fit into the tube. Sensors have to be removed to replace the heater element. 11 Ohms of resistance between heater terminals. It is important to purchase a quality heater element to ensure years of service. If using a salt water system on your hot tub, it is wise to replace the heater element with a titanium element.