Elastic HELLO SLEEP - LET THE AIR FLOW, LITERALLY - The ups and downs and in-betweens of this specially engineered, cooling gel-infused topper promote airflow throughout its conforming memory foam layer to dissipate heat while providing superior softness and comfort.Product Note: Please allow 24 - 72 hours for your Mattress to regain its full shape. Any memory foam will expand faster in a warmer room. In cold temperature, at delivery, your mattress may take a bit longer to return to full sized from its compressed state.The expansion time of the mattress will vary as per the surrounding A COOLING EMBRACE - This 1.5 inch layer is constructed with supportive memory foam swirled with cooling gel; fits under any standard or deep pocket fitted sheet CERTIPUR US CERTIFIED - Highest quality foam is CertiPUR US Certified for durability, performance, and content EXPERTLY PACKAGED - Our technology allows this topper to be efficiently compressed into one box that’s easily shipped to your door; simply unbox, unroll and this topper does the rest, expanding to its original shape within 72 hours Worry-free 5 year limited warranty included; a new foam scent is normal and should dissipate within 72 hours