10" thick with 2.5" HD memory foam layer and 7.5" foam support base, Twin Size 38 x 75 x 10 * Open cell technology allows air to flow through, keeping the mattress cool and comfortable * Conforms to the curves of your body for greater pressure relief and proper spinal alignment * Reduces tossing and turning, eliminates motion transfer, and provides a great nights sleep. Naturally anti-microbial, hypoallergenic, and dust mite resistant. * Mattress compressed and rolled for shipping -- easy to carry and saves you money on shipping costs, 25-year warranty