Perfect for monitoring exact refrigerator or freezer temperaturesThe CDN ProAccurate Refrigerator/Freezer Thermometer is NSF certified and has a measurement range of -40 to +27CTips Frost buildup makes it harder for the freezer to maintain the proper temperature. Defrost when necessary. To preserve the taste and texture of food, freeze quickly and thaw slowly. Air causes freezer burn by removing moisture from food. Seal food securely with a good-quality wrappercontainer. Do not put a large quantity of unfrozen food into the freezer simultaneously. This could partially thaw the food already in the freezer by raising freezer temperature. Check the doors rubber seal periodically to ensurethat cold air is not leaking out.Close the door on a dollar bill. If the bill can bewithdrawn easily without opening the door, consider having the seal replacedFeatures:Measurement Range: -40 to +27CNSFCertifiedFor Refrigerator/FreezerTarget range indicationPolycarbonate caseNon-mercuric columnTemperature guide on the thermometer2-way mounting: stand/hang