The TROND Halo 10W led desk lamp emits a beam of localized light without disturbing others. It is perfect for reading, writing, crafting, painting, sewing, knitting, crocheting, jigsaw, etc. The lamp doesn't have a built-in battery and can ONLY be powered by the included power adapter; the memory function continues to work even if the power cuts off. Swiping at the dimmer groove, you can adjust the brightness up to 7 levels, fun & flexible gooseneck arm(42cm / 16.5 fully extended) allows you to bend the lamp neck and direct the light with ease. Designed with no physical buttons, lightly slide your finger across the control groove to set the brightness level and the lighting mode that you like.