Lamp life 50000 hours DC 5V / 500mA The brightness level can be adjusted to 3 levels by tapping the square button. 1 hour battery life, 1.5-2 hours (depending on brightness) The charger can be plugged into the charger via a USB cable (to a computer). Powerbank battery backup or through a plug adapter. how to use. Just touch the power button to turn it on. Makes you comfortable. And carry it anywhere with the built-in battery. You have to love the use that makes you comfortable. Rechargeable with Micro usb cable when the battery is empty.