Support: With a 13.5 gauge open coil spring unit, plus a layer of visco-elastic memory foam. Mattress: Get a deep quilted semi-ortho spring mattress. Firmness: Single sided, with a medium soft firmness that contours to the user's body shape. Cooling: Features a micro-quilted, cool touch top with a wavy design. Sizes: 2ft6 (small single), 3ft (single), 4ft (small double), 4ft6 (double) or 5ft (king)! Clean build: Hypoallergenic, anti-bacterial and with anti-dust mite properties. Deep Quilted Semi-Ortho Spring Mattress | Living Social