Standard meter from the Milwaukee brand, which already gives you more confidence than conventional economical meters for a little more price. A meter that will last for years with your care. Introduce the probe into the nutrient solution and you will know the pH instantly on its digital screen. Automatically compensates temperature to avoid erroneous readings. An economical but effective meter. To calibrate it you will need a Ph7 calibration fluid (sold separately) and the help of the included screwdriver. We put the tip of the meter into the liquid and regulate with the screwdriver until we reach the Ph7 level. You can make it more precise if we regulate it later with liquid 4, but with 7 it will already be quite precise.