I'll give you a hint:

It is not meant for trimming cigars or performing circumcisions, and it'd be of no use if you needed to open a wine bottle.

So what is it?

It's a chestnutter! If you knew the answer to this, you're a nuttier individual than me. I've spent quite a few autumn afternoons trying not to slice my fingers off while scoring X's into the faces of chestnuts—so they don't explode while roasting, open fire or not. Still, I have never once thought about sinking $30 (wait, $30???) into something called a chestnutter. I am willing to bet you can't even ship those to certain southern states, just because of the name.

Source: http://gizmodo.com