The 4kW Heater Assembly with M7 Sensors and Studs is a powerful and reliable flow-through heater designed to maintain optimal water temperature in spas and hot tubs. Featuring advanced M7 sensor technology, this heater ensures precise internal temperature regulation without the need for external pressure switches, simplifying installation and boosting long-term performance. Its stainless steel construction enhances durability and corrosion resistance, making it ideal for continuous operation in high-moisture environments. Compatible with both 110V and 220V systems, this heater is a versatile and energy-efficient solution for a wide range of spa control setups.