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I Believe it is both. Looking closely at the pic you can see those rings have what looks like a collar laying on the vertical surface; across the seams where the rings separate. I'd say those are 1'' i.d/ 30mm o.d. plastic? sleeve inserts, allowing use of both sizes with a single mount.
I use a similar brownells insert sleeve on my cz, in order to fit a 7/8'' Hi-lux scope into 1'' Warne QD rings. The sleeves on my rig felt just slightly too loose for my liking, so i shimmed inside each ring with a single 1/8'' piece of electrical tape, and it has stayed true through hundreds of rounds and taking the scope off/on again to use my iorns.
Full Disclosure: I do not own this particular mount as of yet, but I may very soon.