I bought this pillow because it was advertised as 5 inches thick. We have hardwood floors, so I wanted my dog to have a nice cushy napping spot on the pillow. Unfortunately, the filling is so soft that my dog sinks right down to the hardwood floor, so she really doesn't get the support and cushion I had hoped she would. The filling is not foam, but rather a very flimsy, airy polyester batting. I solved the problem by stuffing a folded egg crate mattress ($11 at Wal-Mart) into the zippered case.