Designed with cooling gel memory foam, this mattress seamlessly blends value and convenience with the durability and trusted comfort Serta is known for. This collection offers all-foam and hybrid designs with 3 zones for lower back support and breathable fabric, so you wake up refreshed. Serta® Mattress-in-a-Box collection delivers comfort at a value with convenient delivery—so you can rest easy night after night.Only available in select modelsFirm - Ideal for stomach and back sleepers with extra supportConvenient Delivery: Restful sleep delivered to your door—just unbox, unroll, and unwind.Breathable Fabric - A soft, breathable cover helps you rest and wake refreshed.3 Support Zones - zones provide lower back support for classic comfort.Available in select models onlyCool Twist® Gel Memory Foam - Cooling gel swirled into premium memory foam offers enhanced airflow, heat dissipation, and contouring comfortSerta® Foam Core: Durable, consistent support from edge to edge, so you're comfortably supported no matter your sleep positionAssembled in USAAdjustable Base CompatibleMattress Top Type: Tight TopMattress Type: Mattress In A Box, Memory FoamIncluded: 1 Mattress(es)Features: Cooling Layer, Mattress In A Box, Foam Layer, Full Support, Cushioning LayerAdditional Information: Suitable for Adjustable Bed Frames, Relieves Pressure Points, Eliminates Motion Transfer, Conforms To BodyManufacturer Warranty: 10 Year LimitedBed Size: TwinMeasurements: 74.5 Length/Inches, 38 Width/Inches, 10 Height/InchesMaximum Weight Limit: 850 LbsBase Material: 60% Foam, 40% PolyurethaneComfort Type: FirmCare: Spot CleanCertifications And Listings: Certipur-Us CertifiedCountry of Origin: Made in US Mattress arrives compressed in a box and then regains its size and shape after opening. Serta Classic 12" Firm Foam Mattress a Box