Didn’t even last 3 months.  I have severe rheumatoid arthritis & need comfort. I don’t move around much but it developed splits completely through the 3 inches.  It was on a new mattress so wasn’t on a lumpy, uneven surface so no reason for it.  It was great while it lasted but that’s too expensive for 3 months usage.  I’ve bought another brand in the past that lasted 4 years & was ok then but wanted a new one.