A zero-ohm link or zero-ohm resistor is a wire link used to connect traces on a printed circuit board that is packaged in the same format as a resistor. This format allows it to be placed on the circuit board using same automated equipment used to place other resistors instead of requiring a separate machine to install a jumper or other wire. Zero-ohm resistors may be packaged like cylindrical resistors, or like surface-mount resistors.
The resistance is only approximately zero; only a maximum (typically 10–50 mΩ) is specified. A fractional tolerance (as a percentage of the zero-ohm ideal value) would be infinite and is not specified.
An axial through-hole zero-ohm resistor is generally marked with a single black band, the symbol for 0 in the resistor color code. Surface-mount resistors are generally marked with a single "0" or "000".