Mine was the older version, with a permanently attached cable that terminates to a connector that holds the two Kelvin leads. Basically no replacements available. At some point they changed to the updated connector version.
With the Kelvin leads still on the test wire, I transferred it to my 250 mA current source on the Force leads, and measured the voltage on the Sense leads. I got 0.097 mV. Therefore, as a calibration datapoint I get 0.097 mV / 250 mA = 0.388 mOhms. I looks like I'm directly measuring around 0.393 mOhms, so compared to the other values it's doing very well.