Sprung: With 13.5 open coil bonnell spring for a longer life. Hypoallergenic: Superb for people with asthma as the foam is anti-microbial and dust mite preventative - ideal for a fresh and healthy sleeping environment. Sizes: Choose small single, single, small double, double, king or super king. Comfort: A 15cm mattress with a medium firm feel. Memory foam layer: Supports and contours to the shape of your body which encourages your muscles to fully rest and relax while sleeping. Mattress: Get a comfy night of sleep with a memory foam sprung mattress. Memory Foam Open Sprung Mattress | Living Social | Living Social