The Zinus Cooling Essential Mattress Bundle includes a 5 inch thick twin size mattress and a Zinus SmartBase essential foundation. The mattress has a 13 inch box spring alternative with a breathable, cooling cover made of bamboo that encourages airflow to keep you cool. It features 2 inches of memory foam for comfort and support, with a 2.5 inch transition zone and a 4 inch thick bamboo slat base. The twin size mattress supports up to 250 lbs.The SmartBase essential foundation has a durable, heavy-duty steel frame with multiple points of contact to the floor for stability. It combines solid steel with sustainable bamboo slats for optimal, long-lasting support up to 350 lbs for twin and twin XL sizes, and 700 lbs for all other sizes. The foundation is 13 inches tall, with 4 inches of memory foam and 2.5 inches of transition zone. The Zinus Cooling Essential Mattress Bundle provides a dependable, even surface for your spring, memory foam, or hybrid mattress to rest on. It's expertly packaged for efficient compression and easy shipment. The nearly 13 inches of clearance space under the frame provides valuable storage room to keep everything neat and out of the way.