This simple tool protects your USB-C device (Drive, SSD, etc) when you plug it into a computer with a bad USB-C port.
The newer MacBooks with USB-C have a nasty tendency to output 20 volts on the USB-C port when a CD32xx chip in the computer dies. That in turn will kill the drive that you plugged into the USB-C port to test the machine...
This tool has a LED on both sides of the board. If the output voltage is above 5.4 volts the red LED will light up to warn you and it will NOT pass that voltage onto the other side. Only if the voltage is correct (i.e. 5 volts) the voltage will be passed through and the LED will light up green.
There is also some extra protection (ESD diodes) on the data lines. With some luck those will protect your data lines if there are wrong voltages there, but this is less than a full protection. (But much more than nothing.)
A4629: 65 euro
All prices include shipping world wide.