When it comes to your comfort, discover the Sierra Sleep 12-inch twin mattress. Its thick layer of memory foam contours to your body delivering amazing support, pressure relief and comfort. The memory foam layer is supported by a super thick layer of firm support foam. This helps reduce motion transfer so you and your partner can enjoy an undisturbed sleep. Plus, this mattress is made of hypoallergenic material, keeping dust mites, pollen, mold and pet dander out.