A firm mattress delivers the support babies need, and Serta's Perfect Start Crib Mattress is designed with all the features you'd hope to find in your child's first mattress: a convenient waterproof cover to protect against accidents, cloth binding for long-lasting durability, plus a lightweight construction that's finished with square corners which helps for a secure fit inside the crib. This comfortable crib mattress is also Green Guard Gold certified. What does that mean for you. It means this mattress meets the strictest standards offered by the Green Guard Environmental Institute, which certifies products for low chemical emissions to help improve indoor air quality. So when you purchase this mattress you can spend less time worrying about what your baby's sleeping on, and more time bonding with them. Innerspring coils Recommended Location:Indoor.