1. Built-in battery: The desk lamp has a built-in rechargeable battery, which can work by battery or USB data cable 2. There is no built-in battery, the table lamp has no built-in battery, and it can only work by USB cable 3. How to set the time: Long press the "Mode" button, the number will flash, then press "Up" and "Down" to set the time, during which you can short press the "Mode" button to switch between time\date\year. 4. How to adjust the brightness: Long press the power button to start adjusting the brightness
