Serta iComfort® Memory Foam features zoned support from memory foam layers for contouring pressure-relief and breathability. With alternating levels of firmness, ergonomically design support zones in every Serta® mattress are designed to keep your body aligned as you sleep. Medium - Perfect for all sleepers-side, back, stomach or combination sleepers. CoolFeel™ Fabric keeps you comfortable throughout the night. Our PerfectConform™ Memory Foam contours and cradles your pressure points for rejuvenating sleep. Our 5 ZoneResponse™ Design provides head-to-toe comfort and support for restorative sleep. Your new mattress may initially feel firmer than expected. Please allow up to 60 days to acclimate to your new mattress as it naturally adjusts to contour, comfort, and support you best. CertiPUR-US(r) Certified. Designed and Built in USA. Adjustable Friendly. 10 Year Warranty  Our Serta® 9" flat mattress foundation is a box spring alternative and is designed for long-lasting support and reduced motion for an indulgent night’s sleep.  Mattress Top Type: Tight Top Mattress Type: Memory Foam Included: 1 Box Spring(s), 1 Mattress(es) Features: Foam Layer, Zone Quilting, Cushioning Layer, Temperature Regulating, Cooling Layer, Full Support Additional Information: Conforms To Body, Suitable for Adjustable Bed Frames, Relieves Pressure Points, Eliminates Motion Transfer Manufacturer Warranty: 10 Year Limited Bed Size: Twin Xl Measurements: 79.5 Length/Inches, 38 Width/Inches, 13 Height/Inches Maximum Weight Limit: 850 Lbs Base Material: 100% Foam Comfort Type: Medium Mattress + Box Spring Measurements: 79.5 Length/Inches, 38 Width/Inches, 22 Height/Inches Care: Spot Clean Certifications And Listings: Certipur-Us Certified Country of Origin: Made in US Set includes mattress plus box spring/foundation. King and Cal. King mattress sets feature 2-piece side-by-side foundations for easier navigation in tight spaces.