The Milwaukee Sharp T75 meter gives you automatic temperature compensation for accurate results. Because it has a replaceable electrode (part #MA73075), you can expect to use it for many years. Battery life is 250 hours of continuous use. It takes three (3) 1.5V batteries, which are included. Milwaukee Sharp T75 specifications: Range: 0 - 1990 ppm Resolution: 1 ppm Accuracy: ± 2% full scale Calibration: Manual 1 point Electrode: Replaceable MA73075 Temperature Compensation: Automatic 0 - 50°C Battery Life: 250 hours of continuous use Battery Type: 3 x 1.5V (included) Environment: 0 - 50°C / 100% RH