McKesson Digital Refrigerator / Freezer Thermometer with Alarm Fahrenheit / Celsius -58° to +158°F (-50° to +70°C) Glycol Bottle Probe Multiple Mounting Options Battery Operated (1074438_EA) 1/EACertified, serialized and traceable and has been tested against a standard, calibrated at the National Institute of Standards and Technology (NIST). Temperature certified to monitor refrigerators or freezers Probe is housed in a 5 mL, unbreakable plastic vial filled with a Bio Safe Glycol Water medium and allows internal or external sensor reading display. Alarm display with real time and date stamp, low high limit settings, with visual, flashing LED