Digital Refrigerator / Freezer Thermometer with Alarm McKesson Fahrenheit / Celsius -58° to +158°F (-50° to +70°C) 2 Glycol Bottle Probes Multiple Mounting Options Battery OperatedTriple display allows multiple mode options simultaneously showing high, low and current temperature or high, low and current humidity. Certified, serialized and traceable and has been tested against a standard, calibrated at the National Institute of Standards and Technology (NIST). Temperature certified with two probes to monitor refrigerators and or freezers simultaneously Dual probe unit, housed in an unbreakable plastic vial filled with a Bio