Castrating device?
How did you get that?
It's a bloodless castrator. It works by slipping an elastic band over the testicles.
This is the old fashioned version
A good few years ago I was taken home by my then girlfriend to meet her parents, who lived a few miles out of town in a Shepherd's cottage (he was a herd) - I walked into the kitchen and he's cleaning a gadget like that, but very rusty. Stupid here asked what it was, he told me while demonstrating the action

. So that was me put in my place.