Need Help Deciding

There are two sizes for a full size truck and two sizes for a mid sized truck. They are universal so that if you change trucks you can keep the camper and move it onto your new truck. It bolts into the bed, the same way I think as a fifth wheel hitch receiver. It is very light to lift off and can be stored on the ground - does not need to be elevated. Seems very practical. Here is another link showing the models:
https://www.youtube.com/watch?v=qbWYfjoIWoA

I found out about it by looking for light weight truck campers on youtube.