Features: 1. 100% brand new and high quality 2. The water flow sensor is made of high quality material, long service life. 3. It can be installed at the water inlet of the water machine to detect the inflow 4. Small body and stable performance 5. Suitable for water cooler, coffee machine, water filter Specification: Condition: 100% brand new Model: YF-S401 Monitoring range: 0.3-6L Accuracy: 3% Connection method: Red +, Black -, Yellow for signal output (NPN pulse signal) Water pressure resistance: 0.35MPa Operating voltage range: DC5~24V Insulation resistance: 100M Accuracy: (in 0.15-3L/Min) 2% Flow pulse characteristics: f=(73*Q)2% Q=L/Min Output pulse high level: DC 4.7V (input voltage DC 5V) Output pulse ratio: 50% 10% Package list: 1*Water flow sensor 1100% brand new and high quality. 2The water flow sensor is made of high quality material, long service life. 3It can be installed at the water inlet of the water machine to detect the inflow 4Small body and stable performance 5Suitable for water cooler, coffee machine, water filter