Applicable for home, office, car, schools, hotels, laboratories, kindergartens, aquaculture, instrument workshop, libraries, schools, factories and places equipped with air condition, etc. This portable hygrometer thermometer Measures Indoor humidity and temperature in time, help to adjust the humidifier, dehumidifier settings and humidistats, great for monitoring family‘’s living conditions and health by preventing colds, dry skin, asthma, mold. Fast response that measures every 10 seconds with 24 sensitive VENTS to provide updated and accurate readings, wide measuring range that measures temperature from 0.0° to 50.0°, measures humidity from 10% to 99%. (Please allow for a certain amount of error) Temperature range is Celsius only on this model, bright and black front panel with a clear LCD display, easy to read even from a far distance. Measuring humidity accuracy: + 5% Humidity display resolution: 1%RH Measuring temperature range :0°c to 50℃ Celsius Measurement temperature accuracy: + 1℃ Celsius Temperature display resolution: 0.1℃ Celsius Install panel hole size: D42mm Operating Voltage: 1.5V, one button cell size LR44 colour:Black Material:Plastic shell ABS size: 45*15.5mm Package Contents: 20 *digital hygrometer 20 *Button Battery Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.