1/8" luan plywood, the same stuff the original was made of. Like I mentioned above, I contacted Jayco, explained to them what I had to fix and emailed pictures, thinking they would be nice and send me a section of the wall covering material for having to deal with and fix THEIR issues.
They just blew me off, and told me to contact my dealer (who been useless, so far). That's Jayco customer service...
2019 Redhawk 24B