Description: This is digital 0.7 inch LCD TDS meter water quality purity tester blue Range: 0-9990ppm Resolution: 1ppm (0-000ppm) 10ppm (1000-9990ppm) Calibration: Factory calibrated Auto shut-off: 10 minutes Temperature compensation: Automatic Operating temperature: 0 C to 50 C Power supply: 2 x 1.5V battery (button cell) Size: 142 x 25 x 15mm Package included: 1 x TDS meter 1 x Leather sheath 2 x 1.5V battery 1 x English manual