Double Memory Foam Mattresses and King Size Memory Foam Mattreses by Ergoflex. The Ergo Flex(tm) Deluxe 3rd generation HD visco-elastic memory foam mattress - The nights sleep you've always dreamed of...The Ergo Flex(tm) memory foam mattress is a temperature sensitive, pressure-relieving mattress that moulds itself to the contours of your body. The Ergo Flex(tm) memory foam mattress gives your body optimum support and comfort meaning a restful and more comfortable sleep. Ergo Flex's(tm) Visco-Elastic Memory foam mattresses are commended by medical professionals across Scandinavia and used in the health sector throughout mainland Europe due to their widely recognised therapeutic benefits.