I would describe it as a foam, medium-firm, thick, full mattress. It is extremely comfortable and I am honestly so sad that I have to part with it but I'm moving down to LA and don't have the vehicle to take it with me. It's in good condition. There are a few water stains that probably happened a year ago probably? I forget it's there since there's always a cover on anyway. I am asking for $200 or best offer. I live in Palo Alto, just outside of Stanford's campus.