Zinus Ultima Comfort 8 Inch Spring Mattress,&nbsp;Twin Firm, customized support from Pressure Relieving Comfort Foam and iCoil Pocketed Springs iCoil system is comprised of hundreds of independent iCoils to virtually eliminate any motion transfer Only the Highest Quality of Foam-Foam is CertiPUR - US Certified for durability, performance, and content Smartly Shipped - Our patented technology allows our mattresses to be efficiently compressed, rolled and shipped in a box conveniently to your door Worry free 10 year limited warranty