We placed this mattress on a platform base and did not need a traditional box spring. Our sheets happen to be for an extra deep mattress, so they fit perfectly. My husband and I have back issues and find firm mattresses to be the best. This mattress is Extra firm which allows us to kind of float on the top and there is no sinking in feeling. It is more like subtle comfort on the pressure points allowing for a super comfortable and restful sleep. There is no "bounce" when one turns over or gets up in the middle of the night.