This Diamond Crown state-of-the-art Precision Hygrometer with its accurate technology and internal microprocessor, boasts a contemporary, low profile design. This award-winning hygrometer features a one-of-a-kind humidification adjustment panel, so that relative humidity calculations can be easily adjusted up or down to account for differences in barometric pressure. Its easy-to-read large LCD screen instantly converts the temperature reading from Fahrenheit to Celsius to suit the users preferences at the flip of the switch. The Diamond Crown Digital Hygrometer allows you to: Read both humidity level and temperature Powered by battery so no need to plug in to an outlet Easily change the temperature reading from Fahrenheit to Celsius Comes with full instructions on how to use Size: 3" x 2 1/4" x 3/4" Lifetime Guarantee Lifetime Guarantee from the manufacturer (J.C. Newman) We assist you in filing guarantees with the manufacturer