I have a King Size Sleep Number Memory Foam Mattress  pad that is 2 inches thick and pretty sure it is the cooling gel memory foam. Very heavy duty says it weighs 28 lbs and I believe it as it is heavy.   Paid $200 for it new.  I had a sleep number bed and didn’t like the bed so bought this and used it like 3 weeks and didn’t like memory foam.  Only 1 very tiny spot on top and a couple marks from being stored under the bed.  if interested message me on here if interested.  $75