The Waterproof UEi PDT550 Digital Thermometer is designed for easy temperature monitoring in HVAC, Refrigeration, Food Service, and Automotive applications. The UEi PDT550 measures - 58 to +572 F (-50 to +300 C). Use the built-on magnetic mount for hands-free operation. Record Maximum and Minimum Temperatures. Use HOLD to freeze the current reading. Change batteries easily. Use the protective cover to keep the temperature probe safe.