Features 100% brand new and high quality. The water flow sensor is made of high quality material, long service life. It can install at the water inlet of the water machine to detect the influent flow Small body and stable performance Suitable for water cooler, coffee machine, water filter Specification:Condition: 100% Brand NewModel: YF-S402Monitoring Range: 0.3-6LAccuracy: 3%Wiring Method: Red +, Black -, Yellow For Signal Output (NPN Pulse Signal)Water Pressure Resistance: 0.35MPaOperating Voltage Range: DC5~24VInsulation Resistance: >100MΩAccuracy: (in 0.15-3L / Min) ±2%Flow Pulse Characteristics: f = (73 * Q)±2% Q = L / MinOutput Pulse High Level: >DC 4.7V (input voltage DC 5V)Output Pulse Duty Cycle: 50% ±10% Package List:1 * Water Flow Sensor Package List