Give your baby the support and comfort they need without breaking the bank. Our Nighty Night Two in One mattress features 150 heavy duty 15.5 gauge steels coils for maximum durability and support. 9 Gauge border rods for extra strength and support. (The lower the gauge the thicker the steel).Flex-edge clips provide extra side edge support and safety when baby starts to pull themselves up to a standing position or when the mattress is used with a toddler bed.Poly-cotton coil wrap along with polyester padding prevents loss of cushioning material.CertiPUR-US certified soy foam layer on the toddler side for his or her comfort when using the toddler side.The outer cover has a dust mite barrier, is hypo-allergenic, anti-microbial and is made of an easy to clean material that helps make sure your baby's sleeping environment stays sanitary. Natural air flow pocket helps keep mattress fresh. Edge binding is sewn with a lock stitch that helps prevent edge seam from splitting and moisture from entering. Proudly made in the U.S.A. from domestic and imported sources.