Rear "crash core", material?

Hey,

What material is that rear crash core in? Is it one of those materials that sucks alot of water when it's wet?

 

That foam that's between the support and the bumper cover? It's a very firm type of foam (don't know exactly), I had one outside for a while and don't remember it being saturated with water.

 

Thank you and yes, its that yellow foam between the support and the bumper cover that I mean! /ubbthreads/images/graemlins/smile.gif