There was a running change made to the design of the hard oval ring of the QCS oval wrist cuff system to allow the tabs of the Antares glove system to attach. The full retail version of the Antares system came/comes with the updated hard oval rings.
The QCS oval cuff system is made up of three primary parts:
1. a semi-soft PU ring that is glued (and sometimes sewn as well) into the cuff of the drysuit.
2. A rigid oval ring that is used to retain/sandwich the wrist seal with the PU ring and form the oval shape of the cuff system. This was later modified to accept the Antares dryglove system.
3. A wrist seal...this is usually silicone but the system allows for the installation of latex as well.
If your suit came with the QCS oval cuff system pre-installed or you had it installed as an aftermarket option then it would have come with a set of the rigid oval rings as part of the system.
There was an OEM version of the Antares system that drysuit manufacturers and shops could purchase that came with the PU ring, the rigid ovals, the wrist seals, and the Antares glove and spanner rings....the difference is that this package would only have one set of rigid oval rings.
-Z