This will be milled from aluminum. You can see three holes for output, power and sample polarization voltage. There is also a hole for input connector on the other side. For input, output and sample polarization I plan to use BNC connectors, and for the power connector a dedicated three pin military-style connector. I hope to have this machined soon, so I can finish mounting the whole thing.
Also a dedicated sample holder will be milled from non conductive Teflon:
On this image you can see an additional set of clamps with golden needles attached. The needles are used to make an electrical contact with the sample.