What's the purpose of this for a truck camper?

[jaycocreek]

When I bought my truck I asked the owner why the double receiver and he answered the guy before him had a 10ft truck camper on the truck.I just cannot think of a reason to have welded the bottom receiver to the top other than possibly for a beefed up extension?

Any idea's why or what it is used for?

[Lwiddis]

Trailers with different level tongue heights. Much cleaner looking with an adjustable hitch. Also might be used for a homemade step or cargo carrier.