There was a version of thermarest prolite that weighed 16 ounces but had delamination problems
Then, the polite started weighing 18 ounces. They never acknowledged any change, at least when I looked for it. Just, the weight listed started being 18 ounces
My deduction is they changed the foam inside to a more robust version that didn’t delaminate
In my opinion, they should have acknowledged this. They could have advertised that they improved it.
Maybe they didn’t want the liability of the old versions.
But, I still like it. My 16 ounce version delaminated so I bought a new one that was the 18 ounce version. That has not delaminated. But, I am also careful to never put my hand on it with my full body weight, maybe its not the new version
If this fails, ill buy another