I’ve seen one and used one, but I didn’t know they had a name. I thought they were just jar openers. I don’t have one. My jar opener is a Craftsman 16" channel lock pliers .
We have a tool something like this and it is called (by us, anyway) a Jar Wrench.
There is a Kosher rule something like that.
How does it come to pass that?
FYI, I bought some of the Jalapeno spam. I couldn’t tell a difference. Maybe because I only eat spam like once every other year.