I am truly dumbfounded by the poor quality of this Serta topper. The sale price was $38.99 (stating the original price $338.99).  I would have been sick had I paid the original price.  I unboxed and laid it out flat for 4 days, turning it over several times.  As of today, it is still flat like a stepped-on slice of bread. The covering is loose and has gaps in several places. It continues to have sharp fold lines in the foam the full length of the topper. At best it would pass for the little rubber mat my grandson uses in daycare to nap on.   This is a Serta failure, not Wayfair. It was boxed well and I received it as promised.  DO NOT buy this item unless you need a heavy rubber sleeping mat.