Mattress: Get a 10" Cool Blue memory sprung mattress. Sprung: 13.5 open coil Bonnell spring for a longer life. Firmness: Medium comfort rating with a 9-10" depth. Six sizes: Small single, single, small double, double, king or super king. Cool Blue memory foam: Contours to your body's natural shape and promotes a cool and comforting nights sleep. Hypoallergenic: Hypoallergenic and dust mite resistant for a fresh and healthy sleeping environment. Cool Blue Memory Sprung Mattress | Single | Living Social