Had I not looked it up, I would have thought it was a version of a pair of door window suction cups. They attached to the inside of the window, go over the door frame, and attach to the outside of the window to hold the window in place while working/removing the mechanisms.

OR a disc rotor anti vibration/silencer for turning rotors.
Attachments
doorsuctioncups.jpg (5.54 KB, 193 downloads)