Mattress: Get a one-sided memory foam mattress. Memory foam: With a layer of memory foam and soft-knit polyester cushioning for extra comfort. One sided: No need to flip your mattress – it’s built to stay supportive over a long period of time. Five sizes: Choose from small single, single, small double, double or king sizes. Temperature regulating: Designed to keep you cool when the weather is warm and provide an ideal sleeping environment.