At the base of all the memory foam mattresses in the Conform line, Sealy puts a firm, high-density foam they call SealySupport™ Gel Base Foam. (703 Reviews) A traditional innerspring mattress that responds to your every … No one tests mattresses like we do. Get performance ratings and pricing on the Sealy Response Performance Chestnut Street Cushion Firm mattress. Posturepedic Chestnut Street 13.5" Cushion Firm Pillow Top Mattress Collection Closeout $1,169.00 - 2,029.00 Following suit with many online mattress brands, Sealy now offers a line of mattresses that are shipped in an easy to move box. Sealy's mattress-in-a-box comes in both memory foam and hybrid mattresses with 8'', 10'', and 12'' profile options. It’s the slab that gives the whole mattress a strong base. Sealy Mattress-in-a-Box. Clear Filters Innerspring Memory Foam Hybrid Shippable Ultra Plush Plush Medium Cushion Firm Firm Ultra Firm $399 to $799 $799 to $1,099 $1,099 to $1,599 $1,599 to $2,499 Buy Online Now Response Line. Whether you prefer springs, memory foam, or a combination of both— Sealy has a mattress to support your needs.