100% Polyester. SIMPLE SETUP AND QUICK EXPANSION: Mattress is compressed, rolled, and sent in a box, open your mattress promptly upon receiving it and allow 24 to 72 hours for full expansion; memory foam mattress may expand more quickly in a warm room. RESPONSIVE HYBRID DESIGN: Get the best of both worlds, when the contouring comfort of memory foam and the durable support of springs combine in our most popular mattress ever. UNBEATABLE VALUE: Comfort meets value when it comes to this affordable memory foam hybrid mattress, it’s available in three different profiles and feels to accommodate sleepers of all styles and all sizes. MEDIUM FIRM FEEL:This mattress combines multiple support and comfort layers to bring you responsive comfort and a medium-firm feel great for back, and stomach sleepers and is ideal for kids rooms, a guest bed, bunk beds, trundle beds, or as an RV mattress. WORRY-FREE WARRANTY: Linenspa mattresses include a limited 10-year warranty, this innerspring and memory foam hybrid mattress is so much more than just a bed in box — it’s the complete package.