"span"TDS/PH/thermometer 3 in 1 Measuring range: pH: 0.00-14.00 ph; TDS: 0-19999 ppm; Resolution: 0.01 ph; 1 ppm Accuracy: ph: +/- 0.05 ph; TDS: +/- 2%; temperature: +/- 0.5 °C Battery: 3*1.5V LR44 button battery (not included) When purchasing the instrument, please pay attention to the parameter information of the product.