Mattress: Get a 10-inch tufted memory foam mattress. Inners: With a 13.5 open coil Bonnell spring for evenly distributed support for the body. Depth: 10-inches deep with a layer of responsive M3 memory foam. Firmness: Medium firmness - perfect for side sleepers! Features: With a hypo-allergenic cover - ideal for allergy sufferers. Size options: Choose from six sizes (see full details for pricing). 10 Memory Foam Spring Mattress | Small | Living Social