Tired of finding frozen lettuce in your fridge or ice cream that is too hard to scoop? To ensure food is stored at ideal and safe temperatures this thermometer measures the precise internal temperature of freezers and refrigerators. Housed in a durable plastic casing the 4-3/4-by-1-1/4-inch thermometer features a red non-mercuric column inside industrial-grade glass. Two stainless-steel clips keep it securely fastened to a shelf. Temperatures read horizontally in a dual scale range of -40 to 80 degrees Fahrenheit (-40 to 27 degrees Celsius). Zones are marked for recommended storage temperatures: a freezer should be set ideally between 0 and -10 degrees Fahrenheit (-17 and -23 degrees Celsius) while a refrigerator should be kept between 34 to 40 (1 to 4.4 degrees Celsius). Colder than that causes lettuce to freeze; warmer and foods spoil too quickly. Certified by the National Sanitation Foundation (NSF) this thermometer has been manufactured to high commercial standards. CDN covers this professional thermometer with a five-year warranty against defects. 5-year warranty Thermometer tests freezer and refrigerator for safe food storage Measures temperatures from -40 to 80 degrees Fahrenheit (-40 to 27 degrees Celsius) Non-mercuric durable laboratory glass column reads horizontally Stainless-steel clips mount thermometer securely