Fabric used for noise reduction.
They actually hold up well. Have been used in many cars.
Odd thing is on the Ranger the felt is in front only.
On my GTI, felt on rear wheels only.
One would think for sound it would be on front mostly by driver.
The felt does hold a lot of dirty. So power washing helps with wide tip.
Fine. Did t even think about them until you brought it up. So I looked and there like new. I take it out on gravel/rocky trails and they're holding up.