The Best Industrial Grade Accuracy: Humidity gauge with built-in Swiss sensors, it detects subtle humidity and temperature changes and updates readings in each 10 seconds. Temperature tolerance is within 0.5℉(-4 to 158℉) and humidity is 2%RH (1 to 99% RH). The digital hygrometer is pre-calibrated for accurate temperature and humidity measurement. Easy-to-Read Backlit Display: Temperature and humidity monitor with 3.5'' large HD LCD screen. A simple touch on the top will turn on backlit for 10 seconds. Clear and power-saving, reading more easily under weak backlit. Reliable operating buttons on the back for manual setting or °F/°C switching. Note: The backlit in the pictures is all in ON state. The backlit is not always on. 24 Hours All-time Max Min Records: The room thermometer displays high and low records for the past 24 hours and All-time; Indoor thermometer measure conditions and identify changes in temperature and humidity instantly. Comfort Indicator ensures proper humidity control, helping you to maintain a comfortable atmosphere in your home. Wide Applications with More Mounting Options: With a retractable stand, two powerful magnets and a wall-mount hole, this digital thermometer indoor can be easily attached to your refrigerator, wall or placed on a table. Suitable for baby’s room, nursery, office, closet, incubator, greenhouse, garden, wine cellar, basement critter terrarium etc. Note: This thermometer cannot connect to phones. Calibration Supported: The monitor can be manually calibrated to improve data readings when product placement or environmental factors impact your data accuracy. Powered by 2x1.5v AAA batteries (not included). SC42 Humidity and temperature monitor is the perfect household device to keep you and your family's living conditions optimal. Built in with high precision sensor, it gives you reliable and highly accurate reading.