Features: 1) PH-901 pen pH tester 2) Range: 0.00 - 14.00 3) Resolution: pH 0.01 4) Accuracy: +/-0.03 / (PH-901A: +/- 0.10)5) Temperature: 5 - 50oC (ATC)6) Calibration: two-point at pH 6.86 and pH 4.01 (or pH 7.0 and pH 4.01)7) Automatic switch-off function: after 10 minutes without pushing buttons8) Low battery9) Accuracy guaranteed 10) DC 4pcs 1.5V batteries11) Plug: fixed electrode producing area:China payment:T/T