MIEO Humidity Monitor with Indoor Thermometer, Digital Hygrometer and Humidity Gauge Indicator with Alarm Clock Acoustic Control Backlight Humidity Monitor Meter for Home, Office, Greenhouse (Black) Sound Controlled Backlight The only Sound control backlight thermometer on the Amazon Web, site has improved the traditional touch screen and key activated backlight. It is more convenient to watch temperature and humidity at night and in darkness. 3 Sets of Alarms with SnoozeWhen the alarm sounds, press the LIGHT / SNOOZE button to start snoozing for 5 minutes. You can set the alarm time and press any key to exit the alarm. The 3 group alarm clock function is equivalent to your life assistant, reminding you to get up in the morning / noon conference / evening appointment, etc. Don't worry about forgetting important things. Air Comfort IndicatorHumidity meter with humidity level icon indicates air conditions -- DRY/COMFORT/WET,Also displays the trend of each reading, allowing you to react ahead of time, such as adjusting your thermostat or humidifier.Humidity meter ensures proper humidity control, which is benefit for skin, allergen and other health problem. Two Power ModesWhen powered by three AAA alkaline batteries, the backlight can be activated by patting the palm or table within one meter, and the backlight brightness can last 12 seconds. When powered by DC, under any mode except ringing, press LIGHT/SNZ key , the backlightluminium can be set in the following order:Backlight long lighted  semi-long lighted light off. No RISK 100% quality guarantee, If you have any problems, pls contact us, we will have a best customer service.