The power supply voltage switch, sometimes called the voltage selector switch, is a small switch located on the back of most desktop computer power supply units (PSUs)

This switch is used to set the input voltage to the power supply to 110v/115v or 220v/230v. In other words, it tells the power supply how much power is coming from the power source.

There is no single answer to the question of which voltage you should use. It depends on the country where the power supply is used.

For more information on what voltage to set your power supply switch to, please refer to Voltage Valet's Foreign Outlet Guide.