The UCO Arka USB Charger is also a compact, collapsible lantern that provides up to 180 lumens of light. The lantern is powered by a 4 amp-hour rechargeable battery, and is simply plugged into a normal electrical socket to recharge. The lantern battery can re-charge your other mobile or digital devices using the USB port. The on/off switch controls the brightness of the lantern - just hold the button and it will dim or brighten to the level needed at the moment. Also available is a red-light mode to preserve night-vision. This is helpful for reading maps, and also offers strobe options as an emergency beacon.