Naturepedic EOS Classic MattressDesigned For You (Now and In the Future) With a range of materials and firmness levels, the EOS organic mattress offers a truly customized mattress experience. It also provides flexibility as your needs change over time. After all, the one constant in life is that nothing is really constant. This is true for your comfort preference as well. Never again will you have to buy a whole new mattress because you'd like your mattress a bit firmer or softer.