Loose fluff, good drainage
The fluff, particularly the brown parts, just came off in my hands to start with. But after a few washes and some chewing, it seems pretty solid. The pee drains through very well, keeping my puppy dry and clean but he does like to scratch and ruck it up. He doesn't do it excessively but tiny pieces of the non slip backing, now litter my floor. One scratch and it's everywhere. Doesn't seem to have made it ineffective yet though.