Fangrui Product Details [3 Alarm Settings Available]this Digital Alarm Clock Not Only Has 2 Display Modes (12/24h) And Temperature(c/f) , But Also Comes With 3 Groups Of Alarm Settable. Each Alarm Sounds For 1 Minute, Ensuring To Wake You Up Even In The Deepest Sleep [adjustable Brightness]you Can Choose 3-level(from Low To High) Brightness For The Most Appropriate Brightness To Satisfy Your Different Needs. So It Can Protect Your Eyes Well. You Can Also Read Temperature (f/c) From Its [two Power Supply Modes]the Alarm Clock Supports Two Power Modes: Battery Power And Usb Power. Battery Power Is More Convenient (need 4xaaa Batteries, Battery Not Include). Usb Power Supply Is More Energy-efficient And Protects The Environment. It Is Recommended That You Use Usb Power Suppl [sound Control Mode (power-saving Mode)] The Down Button And Choose On:sd, The Screen Turn Off After 10 Seconds. You Can Light Up The Screen By Clapping Your Hands (any Sound Louder Than 60dbm) Or By Tapping The Clock. The Down Button And Choose -:sd T