The rope hooks up to what is called a Fries rig. It is a loop on the end of a bar that extends out from the side of a a center mounted beam on the ceiling. There is one bar on each side of the aircraft, hence two rings, one each side to attach 1 rope per side to. Here are some pics.
Here's mine that I built for my MH-60L DAP:
More shots of mine here: http://photobucket.com/albums/v231/HeavyArty/MH-60L%20DAP/
Hope that helps.
Gino P. Quintiliani - Field Artillery - The KING of BATTLE!!!
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"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." -- George Orwell