Can someone tell me what they are exactly

Remember these, Dave? The pans don't have a bolt that runs through them.

Yes I rember now, older traps, I have 1 of those traps in the pic

Caught my first coon in one way back in the early sixties in a blind trail set along the Chippewa river. I bought it new from Don's sport shop when i was in 8th grade. Got my first mink in one a few years later.
I still have some victors from over 60 years ago I use for mink and rats along with various other brands I've accumulated over the years. They are a good trap on the waterline.

Over rated in my humble opinion, but to each their own. Still room for a mink to step on all sides of the pan, and not fire the trap.

I like’em