Lullaby Earth Super Lightweight Crib Mattress With Organic Quilted Crib Mattress Pad, you can keep your baby safe without exposing him or her to the toxic chemicals other companies use in their crib mattresses. Lullaby Earth Super Lightweight Crib Mattress Features: Air-Core Foam Lullaby Earth uses a major new innovation - Air-Core Foam made with food-grade, low density polyethylene - without all the chemicals used in other types of foam. Air-Core is a network of closed cell air pockets that provide a firm and comfortable base without the chemical issues of polyurethane foam and the allergenic concerns of latex rubber. No Toxic Off-Gassing - GREENGUARD SELECT Certified Lullaby Earth is certified with new stricter and most stringent standard called GREENGUARD SELECT. Also GREENGUARD certified to the Children & Schools Standard and recommended by Healthy Child Healthy World. Comes with a Organic Quilted Pad Cover (Not affiliated with Lullaby Earth brand) has a top layer made of organic cotton interlock. The middle layer is 100% breathable polyester. The back layer is waterproof breathable polyester. The cover measures 28" x 52". This can be machine washed cold with like colors, mild detergent, gentle cycle and use non chlorine bleach when needed.