Hanna HI-98107 Phep pH pocket meter.
The Hanna phep is probably the best selling pH meter in the world. The clear LCD display shows pH to 0.1pH resolution and the meter has an accuracy of 0.1pH.
Calibration of pH can be carried out at either 1 or 2 points (usually pH 4 and 7 buffer values) quickly and easily. The electrode is housed within the pocket sized case and is ready for use as soon as the black plastic cap is removed. Simply dip the end of the Phep in the solution to
be measured and read the pH on the clear LCD display.