Firmness: Medium - ideal for those who like to sleep on their side. Memory foam: With a memory foam layer for enhanced comfort. Memory mattress: Get an 800 pocket sprung and memory foam mattress! Pocket sprung: 800 springs provide even weight distribution with no roll-together. Size: Choose single (3ft), small double (3ft), double (4ft6) or king (5ft) sizes. Pocket Sprung & Memory Foam Mattress | Living Social