Unfortunately, the clip is too weak when batteries are inserted in the foot. She holds then only conditionally on the edge on which it is clamped, each more powerful touch can bring the lamp to fall down. The switch was after 2-3 months already broken, so I had to tinker a separate structure to use the lamp further. If the USB cable is plugged in, but not plugged into the USB port, the lamp does not light up (on battery). You have to pull directly from, so they funktoniert on battery.