"This is the Superior depth 9"" version of the Wilson Beds Grey Ortho mattress with twice the polyester comfort fillings on top of the spring unit when compared to our standard version. Built around the traditional double insulated 13.5 gauge open coil spring unit, it has a layer of polyester comfort fillings, a layer of visco-elastic memory foam, and is topped with a quilted Cooltouch top panel for an additional layer of comfort. A single sided medium soft feel 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. Suitable for use by the whole family and all bed base types of the approriate size. Please check mattress depth requirements for bunk beds etc as this is a 9"" deep mattress."