Measuring Range 0.00 - 14.00 pH Resolution 0.01 pH Accuracy < =+/- 0.03 pH Calibration 1 point . 2 point Plug Fixed Electrode . changeable electrode YM-901 Digital pH Meter Tester - Universal Tester! 1. Pen type pH meter 2. Lightweight, compact 3. Read quickly and accurately 4. Switching film 5. Long low battery power consumption 6. Waterproof 7. Features: automatic cutoff switch 8. Low power consumption (as long as there is any view Guarantee the accuracy) 9. Operating Temperatures: 0`C to 50`C (ATC)