" The diameter is about 203mm, the thicknis about 43mm, and the precision is between -40 and 120? / -40 and 50 C to adapt to all climates. And can be used as a decoration for the home to improve your life. Auto Calibration: This thermometer time is an accurate thermometer coil, which can ensure accurate thermometer readings. Automatic calibration, just put it in a fixed position. After 2 hours, the pointer will automatically correspond to the local temperature. No battery needed, energy saving. Coil springs made from special materials use the physical characteristics of "thermal expansion and contraction" to achieve retraction or expansion of the spool to cause the needle to turn. The thermometer can display degrees Celsius, Fahrenheit and humidity at the same time. Classic American style, and fashion. The glass lens is smooth and transparent, and the font is large and clear, easy to identify. The scale can also be easily read from a distance. Product description Features: 100% brand new quality. No battery, energy savings. A simulated hygrometer can help you create a healthy environment for temperature and humidity. Temperature and humidity sensing elements in high precision materials. Specification: Material: iron shell, plastic shell, glass mirror, PVC watch Style: American dial Measuring range: temperature -40 ~ 120F (-40 ~ 50C), humidity 0 ~ 100% Rel Accuracy: Temperature +/- 5F (+/- 2C), humidity +/- 7% (40% to 70% Rel) Size: diameter is 203mm / 7.99in, thickn43mm / 1.69in Weight: about 0.38 kg Package includes: 1 x hygrometer thermometer "