Our Harmony is available in firm or extra firm. This is a great mattress for those that want a firm mattress. It is also good as a child’s first bed in the Firm if looking for one that will last through college and beyond, but still give the support the child needs now for their growing bones. It has a six inch rubber core and is available with a zip outer or available tailored style. The outer, tailored or zip, adds another inch in total giving a 7 inch bed. Our Zip outer Harmony is also available with two 3” cores of same or different firmnesses. Available in Twin, Twin Extra Long, Full, Queen, King, and Cal. King Size in either Firm or Extra Firm. In the case of two 3” cores, it is available in the firmnesses of extra soft, firm, and/or extra firm. On this page we show all of our Tailored Harmonies'. To see our zip outer Harmony's, please go to our "Zip Customizable Mattresses” section in our “Organic Mattresses” section.