24-inch quartz wall clock with thermometer and hygrometer Measures temperatures from -40 to 140 degrees Fahrenheit & humidity from 1 to 99% RH Durable, weather resistant construction Use high-quality alkaline (or lithium in low temperatures) batteries for best performance.NOTE: Refer Installation Manual on Technical Specification before use International products have separate terms, are sold from abroad and may differ from local products, including fit, age ratings, and language of product, labeling or instructions.