During the holidays, many batteries are used for Christmas lights. The Konstsmide 2 x D battery adapter is a replacement for these environmentally harmful alkaline and lithium batteries. The power adapter is connected to the mains and functions as a replacement for the original power cells. The device has a white power cell and a yellow dummy cell. Both units must be inserted into the battery compartment, with the white battery supplying power and the yellow dummy battery completing the power circuit. The Konstsmide 2 x D battery adapter is connected to the mains via the three-meter-long connection cable with plug. For mood lighting that requires a different voltage or a different number of batteries, for example three AAA batteries, you should purchase an equivalent power adapter. Ask a product question