As I recall, they were called "Serprntine" Heads.
I hit a doe with one in 1970. I got about 9" peneteration. Good lung shot that hit right between two ribs.
Devastatig hole.
It was a bitch to sharpen but I managed to get a real good edge on it. I expect that if I had hit a rib solidly, or if I did not have a good sharp edge on it, I would not have gotten good penetration. As Rich indicated, good concept, poor results.
You have to post the item number to reference an e8ay item. If you post the URL the part of it that says "e8ab" comes out as "****". The forum has it set this way because we are not supposed to refernce e8ay here. So when you click on the URL you get nothing