Features: It can be used for water quality testing in the field of domestic water and hydroponics. Its Electrode can measure conductive materials, such as suspended solids, heavy metals and conductive ions in water. This TDS Meter Probe is plug and play and easy to use. Also, the wide supply voltage of 3.3~5.5V and the analog signal. The TDS value can be used as one of the basis for reflecting the cleanliness of water. you can easily DIY a TDS detector, and easily check the cleanliness of the water to make your water quality better.