Features: Product function: Check whether there is-liquid flow in the pipeline: 40-150mVMIN. Product features: small volume/high flow accuracy Photoelectric principle: more hygienic and safe. Working principle: The-pulse signal generated by the impeller cutting light-path flowmeter without-magnet and pure optical induction can be used to measure the water flow by calculating the rotation-time of the impeller which is-more suitable for long-term measurement of drinking water. Application: Water dispenser/water-heater/coffee machine/small flow control application. Applicable scenario: Measure the water flow and output pulse signals. Specifications: Material:Plastic Size:As Picture Shown Note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thanks for your understandings. Package includes: 1x Water Flow Sensor