I thought it looked like a ball thrower for dogs.
Right it's A Ball Thrower for Dogs Used to Throw Channel Cat Chum. That makes for a long title though. Channel Cat Chummer is a lot shorter. Maybe dog ball throw should be the subtitle or something.
If you have a dog thrower, try it and see how it works as a chummer. I'm not claiming to have invented anything new here. But for people who don't have any kind of decent chumming device, this may be a good option for you. Just repurposed a common device many of you are familiar with.
There's a bunch of tools out there for carp fishermen who chum but nothing out there for catfishermen. So I looked an found a Chinese manufacturer who makes these, and I figure they would make good chummers for catfishermen.