The Serta® Serene Sky™ is a cooling and supportive mattress that delivers the kind of comfort you can trust from Serta®. Product Highlights Cool Twist® Gel Foam has cooling gel swirled directly into a breathable foam designed to promote airflow and heat dissipation. The Individually Wrapped Coil Support System provides contouring, cradling support and features Serta's BestEdge® Foam Encasement technology - an extra-deep foam rail to help reduce edge roll-off and extend the sleep surface. Mattress Top Type: Pillow Top Mattress Type: Innerspring Included: 1 Mattress(es), 1 Box Spring(s) Features: Breathable, Cooling, Temperature Regulating, Wrapped Coils, Cushioning Layer, Foam Layer, Cooling Layer, Adjustable Base Compatible Additional Information: Relieves Pressure Points, Suitable for Adjustable Bed Frames, Eliminates Motion Transfer, Conforms To Body Coil Count: 324 Coils Manufacturer Warranty: 10 Year Bed Size: Twin Base Material: 100% Polyester Mattress + Box Spring Measurements: 76 Length/Inches, 40 Width/Inches, 21 Depth/Inches Care: Spot Clean Certifications And Listings: Cpsc - 16 Cfr 1633 Compliant, Cpsc - 16 Cfr 1632 Compliant Country of Origin: Made in US Visit our Furniture & Mattress Customer Care Center for delivery options, protection plans and other services. Problem with an order or need help with a return? Our Furniture & Mattress Customer Service agents will be happy to help. Give us a call at 1-800-442-7902 Don’t forget to print off your delivery checklist to avoid any delays or issues when delivering your item. 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. This mattress meets the requirements of 16CFR Part 1632 (federal flammability (open flame) standard for mattresses and mattress pads This mattress meets the requirements of 16CFR Part 1633 (federal flammability (open flame) standard for mattress sets) when used with foundation