I don't know if thats it, but you could create it via the following:
1) Threaded rod of the desired diameter and threadcount.
2) Delrin/PVC rod (solid, or with a smaller hole than #1).
3) Drill out and tap a thread in the bigger rod.
4) Screw in the smaller threaded rod so it sticks out on both sides.
5) Add a touch of superglue so the center rod doesn't rotate when gently torqued.
6)
7) Profit.
If you want to be really snazzy and prevent the capsule mount ends from experiencing gravitational force/torque in the wrong direction (1 end in the above notes presumes that you're screwing it on "backwards"), you could cut your small rod in to two pieces, reverse one of them, and thread them both in (again, a touch of superglue). Now when you thread your mic clip mounts on the ends the weight of the capsule, being slightly forward (and pulled on by gravity) will torque
into the thread instead of loosening itself.