Are you talking about isoHop perhaps? I bought some since I did a partial boil for a big barley wine and didn't recalculate my hops for it. It turned out being ~14% ABV and 30 IBUs. It was a little expensive ($25, I think) but I was able to use it to bring my beer up to 90 IBUs and it's much more balanced now.
I want to make a half batch and do all of my bittering with it, while the other half uses bittering hops to compare and contrast.