PH-900 Mini pH Tester Range: 0.00—14.00 pH, Resolution: 0.01 pH, Accuracy: ±0.03 pH, Temp. C: 5—50°C, (ATC) Calibration: Two-point at 6.86pH and 4.01pH (or 7.0pH and 4.01pH) Battery Life: DC 4 x 1.5V