It's a sort of plastic plunger. You load the caged magnet into the plunger and stick it in the back of the cows mouth. Press the plunger and the cow swallows it

It's a sort of plastic plunger. You load the caged magnet into the plunger and stick it in the back of the cows mouth. Press the plunger and the cow swallows it. Kind of like giving your pet a tablet, but bigger.