UK (left), US (centre) and European (right) mains plugs. These plugs are designed specifically for use in their respective countries and regions. They all include a live, neutral and earth pin or socket, but take different levels of current due to historical differences from when the electrical power systems were being established. The UK runs on 13 amps, 250 volts, and 50 Hertz; the US and Canada on 15 amps, 125 volts and 60 Hertz; and most of Europe on 16 amps, 250 volts and 50 Hertz. The respective standards are BS 1363, NEMA 5-15 and CEE7/7, and adaptors are required when using equipment abroad. The UK plug has an additional difference, in that it includes a fuse.