FAST AND ACCURATE READINGS: Water quality testers are manufactured to ultra-high standards. TDS meter ranges from 0-9990ppm. The digital water tester delivers fast and accurate readings with just a simple turn on, dip about 1 inch deep into the water, and instantly read the large digital display. SENSITIVE PROBE: The TDS water tester is equipped with a high-quality probe. Simply turn on the meter and gently agitate the water; a stable reading will automatically lock onto the LCD within seconds. The device will automatically turn off if not operated for more than 5 minutes. ACCURATE MEASUREMENT: The TDS meter has an auto-calibration function that adjusts according to water temperature and quality to measure total dissolved solids (TDS) in water. Once the value stabilizes, press and hold HOLD to lock the reading and determine when to change the water filter. LIGHTWEIGHT & PORTABLE: The handheld design is small and convenient, easily fitting into a pocket or bag for use in various settings such as garden hydroponics, agriculture, beer brewing, aquariums, swimming pools, and home drinking water. Color: blue Material: plastic Package Contents: 1 x Water Tester Note: Light reflection and different displays may cause the color of the item in the picture to appear slightly different from the actual product. Measurement allowance error is +/- 1-3cm.