Can anyone confirm that the astro nano 17 mm external hex ratchet retains the sockets?

Also note that the ratchets are 12 point, kind of odd, when the sockets are 6 point. I don't follow why this was done.
The sockets have a cut out around them.

Is this just for an o-ring and doesn't act as a retaining mechanism when paired with the ratchet.
Meaning if you have them in the ratchet, and flip the ratchet over, do the sockets just fall out?
Ok I watched a video on youtube, it does retain the sockets. Anyone know how this is done? A magnet?
What ever the retaining mechanism is or how it works, torque wrench adapters don't have any retaining mechanism.