If you're restoring a mid-50s Ford post sedan, you know the vent window seals are often dried out and cracked.
This is a pair of vertical back edge seals from Carpenter – made specifically for the 1955 and 1956 Ford sedan models.
They go on the back edge of the vent wing window, the vertical strip that seals between the vent glass and the door frame.
Without these, you'll get wind noise, water leaks, and a generally drafty cabin.

These are made from rubber, just like the originals, and they're manufactured right here in the United States.

Installation is a bit fiddly but doable with patience – you'll need to remove the vent window assembly to slide the old seal out and the new one in.
It's a small part but makes a huge difference in cabin comfort and originality.