TWO IN ONE: The mini digital hygrometer thermometer with built-in probe, electronic thermometer and hygrometer for measuring temperature and humidity for indoor use. WIDE TESTING RANGE: Humidity meters measuring range: -58-158 , humidity measuring range: 10%-99%RH. HIGH PRECISION DISPLAY: Humidity Meter measurement accuracy: 2, humidity measurement accuracy: 5%RH. EASY TO INSTALL: Our humidity meters gauge can help you to konw the current temperature and humidity, embedded opening size (1.81x1.06 inch) . If the size is not suitable, it can be fixed with double-sided tape. WIDELY USED: The indoor thermometer hygrometer widely use in greenhouse, garden, guitar case, incubators, brooders, office, cellar, fridge, closet any other place that requires monitoring of temperature and humidity levels. Colour:black Material:ABS Size:about 48 x 28.5 x 15.6mm Package Contents: 12 x Digital Thermometers 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.