Ideal for commercial use, the TDS-3 includes a carrying case with belt clip. It is highly efficent and accurate due to its advanced microprocessor technology. It features a measurment range of 0-9990 ppm. From 0-999 ppm, the resolution is in increments of 1 ppm. From 1000 to 9990 ppm, the resolution is in increments of 10ppm, indicated by a blinking image.