"A new look, rugged ABS casing with sturdy knobs, and a reference chart for pH and temperature on the front panel make PHB-209 an ideal meter for all users. The keypad has membrane keys for changing the mode and knobs for slope and offset calibration. The pH offset and slope are manually adjustable in order to display the calibration concept and the electrode characteristics to the students. Measurements can be performed for pH with manual temperature compensation as well as for REDOX (Reduction Oxidation Potential). The selected temperature is displayed to ensure better accuracy. The LCD displays the temperature comprehensively while manually compensating for its effects. Practicality, simplicity and comprehensive operating procedures in addition to an affordable price make this meter one of the most popular, basic pH meters available today. A rugged double-junction refillable pH electrode and 12VDC power supply are also included in the attractive pricing."