They are based (as you might have guessed) on the classic table football game. But with your desk very much in mind. Of course, they work as an eraser if you need a mistake in pencil correcting. But the rest of the time, when attached to a pencil, you get to play your own football game with a nearby colleague. After all, with two erasers in a pack, why not?
You can buy online for $9.99. Don't let the currency put you off, the retailer does free worldwide shipping.