Measurement range : 0-9990 ppm Tolerance accuracy : +/-2% Battery : 2Ã—LR44 button battery Operating temperature: 0~50??? Size : 155Ã—31Ã—23 mm Test item : Test water purity Advantages : Fast determination, high accuracy, waterproof and auto shut off. Application : Household drinking water, aquarium, swimming pools, ponds, etc. FEATURES: Hold Function Auto-off Function (After 10 min.) Built-in digital thermometer Includes a carrying case with belt clip WELLON High Quality Digital LED TDS meter For Tasting Water Total Dissolved Solids.