PH-I,PH-II(BNC),PH-III(BNC+Cable) Pocket pH Meter Range: 0--14 pH, Accueacy: ±0.1 pH, Resolution: 0.1 pH, Temp.°C: 5—50°C, Calibration: Two-point at 4.01pH and 6.86pH, Battery Life: DC 4 x 1.5V