The Kolcraft Baby Dri crib and toddler bed mattress is exclusive to Babies R Us. Built with an 80 coil interwoven spring system for durability and support, and thick hypoallergenic all-around support wrap that provides a firm foundation so baby doesn"t feel the coil and stays comfortable and supported for years. Waterproof cover and binding so the entire surface can be cleaned with soap and water. The natural airflow pocket keeps the mattress fresh without the use of small metal vents.