Hiletgo Tds Sensor Water Conductivity Sensor Liquid Detection Sensor Water Specifications: Description: Attention: Package included: Wide Voltage Input: 3.3~5.5V; Output Voltage: 0 ~ 2.3V Analog signal output, compatible with most of 5V or 3.3V Arduino controllers AC Excitation Source, effectively prevent probe from polarization Plug and play, easy to use, you can build a TDS detector easily to measure the TDS value of liquid. It can be used in water quality application, such as domestic water, hydroponics. So you can easily DIY a TDS detector to reflect the cleanliness of water to protect your health.