Power Saving Mode: The digital alarm clock will automatically enter power saving mode when powered by 3 AAA batteries (not included). It will not disturb your sleep because the digital clock will not turn on at night unless you wake it up (any sound over 60 dB nearby). Large Screen Digital Alarm Clock: The electronic alarm clock has a 17 cm LED large screen. You can change the alarm format to 12 or 24 hours. There are also 3 brightness levels for you to choose from, making it easier to read. The ultra-thin body is perfect for a nightstand or desk. A good choice to remind you to take a break. Digital Clock with Sound Control: With sound control, any sound over 60 dB near the clock will wake up the alarm LED. In power saving mode, the screen will automatically turn off after 15 seconds, while you can also set the alarm to continuous brightness when powered by USB. Snooze Alarm: You can set 3 alarms to wake you up better. If you don't want to get up immediately after the first alarm goes off, the other two alarms will wake you up after a nap. Long press "ALARM" to set the alarm time and snooze time. Use "UP" and "DOWN" to set the hour and minute. Each snooze time is 1 minute to 60 minutes. USB Powered Electronic Clock: The alarm clock is equipped with a USB power cable. The current local time will be displayed uninterruptedly only when the clock is connected to a power source using the USB cable (included). You can plug it into a power source to keep the screen on.