OK, given I now have the 8720D here myself, I can clarify this, just in case anyone else wants to know.
The connectors are female on the front. However, they have large thread on the nut, which allows them to tighten more securely to the 85131F flexible cables, which have much larger threads than standard female. So a standard 3.5 mm female connector will mount on an 8720D, but it wont be as stable as the correct test cables are.