Zig Zag Extra Deep Sprung Memory Cooling Foam MattressThis Memory Foam Spring Mattress has a total depth of 8 inch (approximately 20cm). It has been designed with a European engineered 13. 5 gauge open coil spring unit which allows the sleepers weight to be distributed evenly across the mattress. With a layer of next generation cooling Memory Foam for the top comfort, the foam moulds and shapes to the contours of the sleepers body providing a medium soft comfort. The Memory Foam keeps the body cool and