Food will not keep as well, or as long, if it is not kept at the proper temperature. The CDN FG80 Pro Accurate Refrigerator/Freezer Thermometer is designed to measure refrigerator and freezer temperatures reliably and accurately. Use it to make sure that your refrigerator and freezer are kept at the proper temperature for better food storage and energy conservation. The professional thermometer features a non-mercury column (red liquid in the thermometer is food-safe oil) housed in a polycarbonate case that is NSF (National Sanitary Foundation) approved. Includes target range indication and temperature guide. 2-way mounting: stand or hang. 5 year limited warranty.