Fangrui Product Details 1. Same Frequency Display: Time Month Day Week Temperature 2. 12/24 Hour System Switching 3. Celsius / Fahrenheit Switching . 4. Calendar: 2000-2099. Usb-powered Dc5v/500ma; Built-in Battery To Keep The Time Display Program Running Internally But Not Visible Time Setting 5. In Time Display Mode, Set Key To Enter Setting Mode, The Sequence Is Year-month-day-hour-minute. 6. Hour Setting: Set To Enter Hour Setting, Hour Zone Blinks, Up/down To Increase/decrease: After Hour Setting Is Complete, Set To Enter Minute Setting As Before. 7. After Setting The Minutes, Set To Return To The Time Display Screen. C/f Switching, In Normal Display Mode, Up To Switch The Temperature Unit C/f, 12/24 Hour System Setting, Down To Switch The 12/24 Hour System. Precaution. Please Use The Clock In A Dry Place, Due To All The Casing, It Can Not Be Used For A Long Time In A Place Where It Is Wet, Trembling, High Temperature Or Keep The Temperature Change. Please Use The Usb Cable Suitable For The Clock. Note: Charging Model: 80