"This is the superior depth 9"" version of the Wilson Beds black border longwave mattress. Built around the traditional double insulated 13.5 gauge open coil spring unit, it has a layer of polyester comfort fillings with twice the fillings above the spring unit when compared to our standard version, a layer of visco-elastic memory foam, and is topped with the Wilson's Longwave Quilted Cooltouch panel. A single sided mattress that should be rotated regularly for best results. Compressed, vacuum packed, rolled and boxed for easy handling and delivery and therefore it does not come with side supports."