<p>We got a very thick one that came in its own zipped cover. I saw them for as much as $150 and got it at Walmart last summer for $75. It is 4" thick and is memory on one side and I think a little eggcrate like or tecxtured on the other… It was not XL but those 3-4 inches were not missed. The school mattress was so thin that we did not have a real problem with sheets fitting even though it is really thick. Once you take it out of its vacuum packed plastic the only problem is that is is HUGE to move when the end of the term comes, but we rolled it up tight as we could and tied spare ribbons around it and dealt with it. As I was rolling it up helping her pack up I asked if she really liked it or just something she slept on because mom gave it to her for graduation and the biggest smile came over her face. She said it was better than great, and that all her friends asked where she got it. She slept like a baby on it.</p>