I can't stress enough that buying this mattress was a waste of money for us. The first few years it was great, but now it has sagged in the middle (it's 4 years old) and it is painful for us to sleep on. We have had the strongest frame you can put underneath it as well, as it is a very heavy mattress. I wake up with a sore back and neck every day. Sure, this mattress has a 20 year warranty, but it has to sink an inch and a half. It hasn't sunk that much, of course, and if we keep it until it sinks and inch and a half, my husband or myself will need back surgery. I'd rather get a new bed than damage my back.