USB lithium battery charging, with screen and 3 small buttons to set hours or minutes. Maximum setting time is 99 hours and 57 minutes. USB charging lasts up to 120 hours. When the lock is engaged, it remains securely closed and cannot be opened manually. Set the time appropriately. The padlock combination is suitable for airport and travel security. Secure your important items anytime to protect your privacy. How to reset the timer lock: 1. Press the center of the LCD screen to remove the protective film. Locate the reset button under the screw on the left side of the screen. 2. Use a metal pin or clip and insert it into the hole to activate the reset function. 3. When a "Bi" sound is heard (in sound mode), the LCD will display properly. The timer has been successfully 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 between the image and the actual item. Measurement error allowed is +/- 1-3cm.