What is this thing in the door jamb area?

[NorCalC20LWB]

Have the fenders off to adjust the doors and see this cardboard looking thing in the jamb area. Can anybody tell me what it is, what it's for, and where I can get new ones? As always, thanks for any input!

[Jcfcamaro]

What year is the cab. I'm looking at my 72 cab and it's not like that at all. I'll be curious to hear what the real experts say.

[chewychevy67]

Door to fender seals. I think they were on 70 and up upper level trucks.

[FirstOwner69]

Those are commonly called dust shields and were installed on high trim level trucks. I have always assumed that they were intended to reduce noise transmission to the cab. The rubber parts are readily available (https://www.classicindustries.com/product/j1016.html), but you have to attach them to the original metal brackets using staples. I believe the staples were included with the shields I ordered for my'69 CST.

[NorCalC20LWB]

Thank you for the replies, I should have included the year/model..72 Cheyenne C20. The old ones are pretty torn up, so not sure if they're doing any good or not, but will replace with new since they are now accessible.