Comfort has never been more convenient. The Serta® Sheep Retreat Medium Gel Memory Foam Mattress-In-A-Box delivers long-lasting comfort to your front door in our smallest carton ever. Thanks to the unique combination of Serta® Gel Memory Foam, Transitional Support Foam, and Foam Core you can get that sleep-til-noon rest you've always wanted. Your new mattress will help you stay cool, cradled, and supported, no matter what way you choose to sleep!