Arctic Fox 24N-5 tear in fiberglass on rounded roof section

You can purchase Eternabond tape in 12 inch wide rolls here. Might be kind of pricy for what you want though. They also sell 6 inch wide rolls much cheaper. I have purchased 4 in rolls from them but that might be a bit too small and the overlap would not fall in the right place.

I think I would use 6 inch to make a temporary fix until you can get to a fiberglass repair place. I am assuming the hole is in the fiberglass part of the rv and not the roof.
Barney