InnerSpace MattressThe InnerSpace memory foam mattress delivers comfort and value. Place on your choice of foundation: traditional box spring, platform bed, or slat bed (as long as slats are no more than 6 inches apart). InnerSpace is the new mattress made of resilient, high-density polyurethane foam that replaces old-fashioned rigid mattress materials and construction with a technologically advanced, scientific approach to a good night's sleep. This mattress technology distributes your body weight and eliminates uncomfortable localized pressure that occurs at the hips, arms, and shoulders. The good news is that you can sleep comfortably all night long.