Water Level Sensor with Optical Sensing Liquid Level Sensor Pipeline Liquid Level Detection Plastic Float Switch Drop Shipping OOTDTY Features: Made of preminum plastic, durbale & long time service. Optical sensing with nice reliability. Compatible with pipelines: Internal Diameter: 4-5MM. Power Supply: 3, analog voltage output Suitable for espresso maker, mop machine, surface washing machine. Specifications: Material: Plastic Power Supply: three Package Includes: 1x Water Level Sensor note: Please allow 1-3cm error thanks to instruction manual measurement. pls make sure you don't mind before you bid. Due to the adaptation between different monitors, the image might not mirror the actual shade of the item.