Inners: Open Coil Bonnell Spring inners provide the mattress with a longer life span - spreads your body weight evenly across the surface and great body contour support. Features: Foam is hypo-allergenic and great for allergy sufferers - 4 way stretch fabric and deep micro quilting used for extra comfort. Mattress: Grab yourself a 13.5 open coil bonnell spring mattress. Depth: Mattress depth is 7" memory foam - a guaranteed great night's sleep! Firmess: With a medium to firm comfort rating - great for side, front and back sleepers. Size options: Choose from 6 sizes - see list and prices below. 13.5 Open Coil Bonnell Spring Mattress | Small | Living Social