These are the soft triangular piece often missing from the 1960-64 Chrysler vent frame.
It is called a division bar cushion. Goers made them years ago but that supply is long gone
so we 3 D printed new ones in a soft durometer. You reuse your old screw to
retain the piece into the vent frame
The right side and the left side pieces are different. We sell them as bag of two.
Available at Forward Look Parts