Our mattress is over 5 years old & has become warped over time. We aren't in a position to purchase a new mattress, so decided to try one of these to help make our bed comfortable again. The mattress came in a box & once unfolded, transformed into the 4 inch topper. I have to say, I haven't slept this good in years. My back has stopped aching & because of the restful sleep, I am waking up happy & ready to start the day. The quality is unbeatable for a fraction of the price of a new mattress.