I'm right there with you. I did a quick google search and this one popped up on Amazon. There is a great video along with pictures. The video gives a great description of how to use the tool. As well as how not to use it. I'm adding it to my list of wants!
The one I borrowed was branded differently but looked exactly like that one in your link. Super handy tool. Not inexpensive but really effective for the instances where you need such a thing. I don't need such a thing often so I'm fortunate that I have someone nice enough to loan me one when I do.