Not what your asking but .....
I find that a cover that's made of Sunbrella fabric will far out last the Tyvek. My Calmark Sunbrella cover is 11 years old and has been used all but 1 year since purchase. I had the ADCO Tyvek cover prior and it was in poor shape after a couple of years.
Good luck in your search.
Al T
Spokane WA
Al and Deedee
Spokane, WA
2008 Winnebago Sightseer 29R
F53 chassis w/ JMcKinley CHF and Brazel's UltraTrac rear trac bar
2006 Honda CR-V, Blue Ox Aventa LX, RoadMaster Even Brake