We have a sleep number mattress for which I have purchased an additional pump that went bad. I was not about to purchase another one; they are expensive, but I was not ready to purchase another mattress either; the sleep number should last another few years. So, I went hunting for a mattress topper and found this one. I swallowed hard and paid the price and am I ever glad I did. It is fabulous. I have no more head, neck, or shoulder pain when I wake up in the mornings. My lower back does not hurt any more either. My husband likes it too. We are happy and delighted.