This wall-mounted hygrometer thermometer is suitable for both indoor & outdoor. Mercury-free analog wall-mounted hygrometer and thermometer with large, easy-to-read temperature readings ranging from -20°C to 50°C (0°F to 120°F). It is used to measure the temperature and humidity in both indoor and outdoor. The wall-mounted plastic case comes with a built-in hanger hole. Recommended hanging on the wall at home, workshop, school, kitchen, warehouse, etc. Do not expose thermometer to heavy shock.