This is a towing attachment, originally for an Earthquake 3" chipper/shredder. It attaches to the handle and the axle, and can be connected to a garden tractor. It is adjustable in length, so I expect it will attach to most small chippers.
Long story short, I burned up my chipper, and suspect this is a clue that I shouldn't own a chipper, and so I expect I should not replace it.
This attachment has a bit of melted plastic on it. This will not affect the functionality.