Rack-Based PDU units are used for taking high voltage and current and reducing it to more common and useful levels, for example from 240V 30A single phase to multiple 120V 15A or 120V 20A plugs. They are used in computer data centers, stage shows, by DJs, and in other electrically intensive applications. Some premium units have features like remote power monitoring and power state control down to the unit or individual plug level. Certain manufactures also include environmental monitoring via RS485, USB, Dallas 1-Wire or Serial ports. The power outlets themselves are typically IEC-C19, IEC-C13 or NEMA 5-20 style outlets.