Zinus Pocketed Spring 6 Inch Classic Mattress,&nbsp;Twin Firm, customized support from Pressure Relieving Comfort Foam and Pocketed Springs High quality, supportive mattress for growing children and young adults Support system is comprised of hundreds of independent pocketed springs to minimize 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