Lower A/C "eyeball" vents are loose

[Cougar_Bill]

Heres a write up on this

A/C Vent Register Felt

I am looking for a good substitute for the felt band on the vent orb in the A/C Vent Registers. Mine were entirely disinigrated. Could not discern width or thickness. Any material and sizing information would be awesome. This is for my 1969 XR7.