Our GoodCook Everyday Refrigerator/Freezer Thermometer is NSF Certified to accurately measure internal refrigerator and freezer temperatures in Fahrenheit and Celsius, ranging from -20° to 80°F and -29° to 26°C. The thermometer is designed to sit on or hang from shelves with a dial that fully rotates for visibility in either position. Face of thermometer includes color-coded food-safe zones to quickly indicate whether your food is safe, freezing, or at risk-for-spoilage, based on the temperature readout.