A. USB lithium battery charging, with a screen and 3 small buttons to set hours or minutes. The maximum setting time is 99 hours and 59 minutes. USB charging lasts for 120 hours. B. When the lock is locked, it may not open easily and it's difficult to open it by hand. Set the time reasonably. The padlock combination is lightweight and suitable for airport and travel safety. You can lock your important items at any time to protect your privacy. C. How to reset the timer lock: If you find you can't operate the timeout or the LCD doesn't display correctly, you can reset the timer in this way: 1. Press the center of the LCD screen to strip the protective film and tear it off. You'll find a hole under a screw on the left side of the screen. 2. Find a metal pin or metal clip and insert it into the hole and then run it. 3. When you hear a "Bi" sound (in sound mode), the LCD will display correctly. The timeout has been successfully reset. 4. Glue the protective film back on. D. Weight: 30g. Colour: black. Material: ABS. Package Contents: 1 * Time Lock. Only the above package content is included, other products are not. Note: Light and different displays may cause the color of the item to be a little different from the real thing. The measurement allowed error is +/- 1 - 3cm.