Half Ohm is a adapter for multimeters that allows you to measure resistance in the milliohm range. The project is open source, the design files are available in KiCad.
Half Ohm milliohm adapter is ready! Multimeter adapter that transforms any multimeter into a precision milliohm meter and debugging device. Notice that your multimeter is useless when measuring small resistances, like connectors or tracks. So did I, so I built this: 1% precise, small and cheap adapter for you. Ultra useful for finding position of shorts on your board. I have already used it tens of times.
Via Electronics Lab.