The Boori Trundle Mattress is a high-quality pocket-spring mattress designed to fit Boori trundle beds. The pocket springs work independently, providing customized support and maximum comfort. The 100% polyester outer layer adds durability and softness. This firm mattress is perfect for those seeking a supportive and stable surface. The mattress is compressed, rolled, and packed in a box, making it easy to transport and store. Please allow some time for it to expand and flatten before use.