Feature: 1. Used to test TDS value of water and conductivity of water to judge whose purity is, and also has function of testing water temperature and ambient temperature. 2. Can be widely used in water treatment industry, drinking water industry, family, personal home travel, field work, etc. as a tool for testing drinking water quality. 3. Platinum electrode design uses a high‑purity Platinum sensor design to ensure accurate and stable measurement values within full range. 4. With one‑point automatic calibration function, instrument allows use of custom calibration fluid during calibration, need to enter known conductivity value in the instrument and immerse sensor in the calibration fluid and then press switch. 5. Simple measurement value lock function, in the conductivity measurement mode, press HOLD key, instrument will automatically lock current measurement value, press again, instrument returns to measurement mode. Specification: Condition: 100% Brand New Item Type: Water Quality Tester Material: ABS Color: Yellow Name: TDS Detection Pen Test Items: Heavy Metals, Total Hardness Power Supply: Button Battery CR2032 3V (Without Battery) Test Range: 0-4999ppm Measurement Accuracy: ±2%, ±0.1℃ Resolution: 0.1. Package List: 1 x TDS Detection Pen1 x Manual1 x Cloth Bag