Mattress Depth: nine to ten inches deep with responsive 40KG/M3 memory foam to mould around the shape of your body. Memory Foam Mattress: Get a wave open sprung quilted memory foam mattress. Open Sprung Mattress: Features a 13.5 open coil bonnell spring to provide even support for all of your body's pressure points. Sizes: This mattress is suitable for all standard sized bed bases, and comes in a variety of sizes (see full details for measurements). Medium Firmness: Features a medium firmness that is perfect for all body types, and for people who like to sleep on their side, front, and back. Cover Material: A deep micro quilted hypoallergenic mattress that features a four way stretch fabric for extra comfort. Open Sprung Quilted Memory Foam Mattress | Small | Living Social