Since LED lighting uses low voltage, 12VDC power supply adapters are an important part in many lamps and fixtures. These 12VDC wall plug adapters plug straight into your wall with no extra switching box like the desktop power supplies. The wall warts have the switching circuitry right in the plug, similar to a phone charger. This way there is no added bulk or anything to hide, an output wire then extends with a 2.1mm male jack that can connect to your source.