Designed for Compatibility: Specifically engineered for Navien NPE (A) Series Tankless Water Heaters, this water flow sensor ensures a perfect fit and optimal functionality, maintaining the integrity and efficiency of your heating system. Part Number 30008571A: This replacement part matches the specific part number 30008571A, guaranteeing reliability , ensuring your water heater operates smoothly without any compatibility issues. Advanced Triple Security Protection: Features include protection against dry burning, overload, and impurity filtration, enhancing the safety and longevity of your water heater for reliable performance. Accurate Flow Control for Energy Conservation: Accurately adjusts heating power based on water usage and activates heating only when needed, reducing standby energy consumption and improving energy efficiency. Cable color may vary; specific color requests cannot be accommodated. Color: Black Material: Plastic Package Contents: 1 x Water Flow Sensor Note: Light reflection and display differences may cause slight variations in color between the image and the actual item. Measurement may vary by +/- 1-3 cm.