I would suggest taking some Epoxy glue with you. They might need to glue your O-Ring back in place should it blow out.
That can happen you know and its not a pretty sight. (Mans hairy ass all up in the air, Watery Do-Do that smells like chit mixed with what ever flavor ass juice they made you dink running all down your hairy butt and legs, and your O-Ring laying in the floor looking like rotten calamari with warts all over it.)
Oooo the embarrassment the embarrassment.
Good luck brother and no worries I am sure it will go well!