USB lithium battery charging, with screen and 3 small buttons to set hours or minutes. The maximum setting time is 99 hours and 59 minutes. USB charging lasts up to 120 hours. When the lock is engaged, it will not open manually. Set the time reasonably. The padlock combination is lightweight and suitable for airport and travel security. You can secure your important items at any time to protect your privacy. How to reset the timer lock: 1. Press the center of the LCD screen to remove the protective film. 2. Locate a small hole under the screw on the left side of the screen. 3. Insert a metal pin or clip into the hole until you hear a "beep" sound (in sound mode). The LCD will display correctly, indicating the timer has been reset. 4. Reapply the protective film. Weight: 30g Color: Black Material: ABS Package Contents: 1 x Time Lock Note: Light and display differences may cause slight color variation from the actual product. Measurement error allowed is +/- 1-3cm.