This Add_on is only made for mutantC_V1.
Proto_board is a dual-purpose prototyping Add-on. Not only does it have a large 0.1" grid prototyping area but it also extends the USB pins to USB port.
You need this parts to make one for your self (this are not affiliate links):
All the PCB and Graber files are in Gitlab and free to donload and use: