condom size

The one you saw in the same dream, probably. Marked "Jumbo".

Judging by the results of a quick Google search, this is probably a set up for spamming.

Just in case you aren't just trying to talk about your penis online...

Condom sizes are mostly marketing, condoms stretch quite a bit (you can put a condom over your entire head and your penis isn't bigger than your head) and most regular condoms work fine for what they do on a variety of sized members. The "magnum" ones have more to do with ego and marketing than functionality.