The PH-2 Pro Professional is a newly created pH meter whose color-changing backlight display looks like litmus paper. It can quickly show readings on LCD displays and can be calibrated automatically when immersed for testing. Calibration can be done with a single click of a button. It comes with a reset function so after turning it on press the on / off key for 3 seconds and then release it. The pH meter has a power-off storage function so data is automatically stored even after you have turned off the battery for a month. It is a versatile meter that can be used in aquariums, fisheries, swimming pools, spas, school laboratories, food and beverage, and drinking water.