55-57 Chevy 2 & 4 Door Hardtop, Convertible and Nomad Window Channel Adjusting Seals.
The seal fits on the side of the door jam and cushions the adjusting bolt from the door jam. This seal helps to keep the dirt out of the door, and is one more of those small rubber parts that will deteriorate in time. Inspect and replace rubber parts such as this regularly. Made in the USA.