Feautres: No battery required (operates on bimetal strip) Record the max-min temperature Anti-rain structure design and can be hung in the outdoor use 2 in 1 Thermometer Hygrometer 2 Units: Celsius and Fahrenheit, / Specifications: Temperature Measuring range: - 20 ~ 50 / 0-120 Humidity Measuring range 0 ~ 100% Resolution Resolution: 1, 2% Accuracy of measurement Accuracy, plus or minus 2 + / - 5%, (40% ~ 70%) Product Size Unite the Size: 128mm / 5inches Note: Item color displayed in photos may be showing slightly different on your computer monitor since monitors are not calibrated same. Please allow 1-3mm slight deviation due to manual measurement. Thank you Package included: 1 * 5" Min Max Thermometer Hygrometer 1 * User Manual