Balboa Heater, Flothru, BWG M7 15"x2", 230v, 5.5KW, Studs, AB Sensors, PlugClick natural chemistry cast iron or bronze 21071504863 cast iron or bronze and free radicals water treatment to compatible Arctic Spas systems 5 kW Output – Designed for dependable heating performance in compatible systems 🔩 Stud Mount Style – Includes stud ends for secure installation 🧪 AB Sensor Compatibility – Works with Balboa AB sensor setups where specified 🔌 PlugClick Connection – Simplifies electrical hookup on approved systems 📏 Compact Size – Measures 15 in x 2 in for compatible FloThru heater applications 🔧 Replacement Use – Ideal for repairing a worn sensor style