Kind of hard to describe Eternabond tape as just "a tape". Don't be deceived by its' name. It is a vinyl type tape with a thick (almost 1/8 inch coating of a very sticky, thick substance that will fit around screw heads and works great when screws are driven directly through it. Many people do that and then put a dab of Dicor self levelling sealant on top of the screw. Make a nearly foolproof fastening.
I have used it on every seam and penetration on my roof many years ago and it still seals as well today as it did on the first day. I certainly would not call it just "a tape"! :B
Barney