Use your Popup Flip Over Gooseneck Hitch to tow with a B&W Companion 5th wheel hitch. This is used for the less than 20,000 pound model.It is the B&W companion model that uses u-bolts for the mounting.
FLC - B&W Companion Adapter.
This is an adapter to use your B&W Companion 5th wheel hitch with a PopUp FlipOver Gooseneck hitch.
For 20,000 pound (new models) use part number FLC-1.