Check out this link http://www.wdc.com/en/products/resources/drivecompatibility/ scroll down and it shows external drive cables. The new drives use the Micro USB and before that it was Mini USB. I’m almost sure they are not a propitiatory cable.
I previously found this page on WD Web Site. Unfortunately it doesn’t give the details I’m looking for. It would help if the illustrations had more details (dimensions, pins, etc.).
I’m still not sure if my unit requires a Mini or Micro on one end.
I even shopped WD’s Web Site hoping to buy a cable but didn’t see my Model No. listed under the available USB cables.