MR16 lamps are regularly used in place of compact fluorescent lamps known as CFLs or standard incandescent light bulbs for applications such as residential lighting and retail lighting. They are well suited to a variety of applications that require directional lighting of low to medium intensity including recessed ceiling lights, desk lamps, landscape lighting, track lighting and retail display lighting. MR16 lamps most often operate at 12 volts, although they are also available in other voltages. Although halogen MR16 lamps can usually operate on either AC or DC voltage, LED devices require DC voltage and will require some kind of transformer in the unit if AC is to be used.