... pH & Temp.* Pen type digital pH meter, all in one, pH electrode is included, easy to use* Data hold function for freezing the desired value* Water ... pH 4.01, pH 7.00, pH 10.01 buffers*Microcomputer circuit, intelligent function, high accuracy* Easy to change the pH ... laboratory, quality control, school & colleges, swimming pools, water conditions* Auto calibration for pH 4.01, pH 7.00 and pH 10. ...