Noticing that "O-RING" is being used as a description for Slipcase.
O-RING is a gasket.
The vertical pass-through cardstock item which fits over the keepcase, etc. is called an O-CARD.
Seems like a good excuse to limit options via drop-down menu(s). Who hasn't heard of an O-Card/J-Card?
Really, I am pretty ignorant about a lot of anal-retentive format/packaging terminology, but "o-ring" just sounds like some weird sex shit. I've never heard anyone describe an O-Card as anything but, excluding (maybe) "wraparound".
I'll be the first to raise their hand and admit fault on this one. I TOTALLY should have used "o-card". I have no idea what the hell I was thinking. Maybe about plumbing supplies?
"Wraparound" can be used to describe certain sexual maneuvers.