Features:1. 100% brand new and high quality2. The water flow sensor is made of high quality material, long service life.3. It can install at the water inlet of the water machine to detect the influent flow4. Small body and stable performance5. Suitable for water cooler, coffee machine, water filterSpecification: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: >100MAccuracy: (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