Hi ash; What they are trying to say I think is, it's easier to hook up the trailers pin box to the trucks 5th wheel with a low profile tool box than a taller tool box that sits above the trucks bed, the taller tool box will obstruck your vision hooking the trucks 5th wheel to the trailers pin box. But both style tool boxes will fit without interfiring with the trailer TRAVELER07
I like the box for the back bumper!