Interchangeable Digital Sensor Probes. Thermistor Sensor For Temperature Measurement, Fast Response Time Dual Display. Dew Point Measurement. PC Interface. 16,000 Records Data Logger. Auto Shut Off For Battery Saving. Extendable Cable. Tilt Stand. DSO stands for Defence Science Organization (one of the Top Government Research Lab For Weaponry andsupposedly the best brain) The legend for Center 318 : All products sold zero defects till today & traceable to NIST.