USB lithium battery charging, with screen and 3 small buttons to set hours or minutes. Maximum setting time is 99 hours and 59 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 for optimal use. The padlock is lightweight and suitable for travel and airport security. Secure your personal 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 to insert into the reset hole and press the button. 3. When a "Bi" sound is heard (in sound mode), the LCD will display correctly. 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 from the actual product. Measurement error allowed is +/- 1-3 cm.