Pack and play Mattress Size 38x26 Noted: Please Choose the right size for a playard, playpen, topper, or crib. Please measure your mattress first to ensure a perfect match for the playpen mattresses. 40D Memory Foam & 30D Foam The pack-and-play mattress is made of 40D memory foam and 30D high-density foam a soft and resilient mattress, that lets your baby sleep comfortably. Waterproof Outer Cover The outer cover of the crib mini padding is made of a 430g white double-sided design and is waterproof keeping the foam always clean and dry. Quality zipper, easy to remove The zipper design is smooth and fluid, and the outer cover is easily removable. Whether you hand wash or machine wash, or even tumble dry, it appears to be a breeze, providing great convenience for everyday cleaning and unexpected situations. Suitable for Differet Stages of Baby Growth Double-Sided Design Compared to other mattresses, we have abandoned the non-slip single-side use design and adopted a double-sided design with the same fabric and a double combination of two foam types. One Side: The 1-inch 40D memory foam, which is soft and comfortable, is suitable for infants over 9 months old.The other side: The 30D high-density foam with high rebound, offers strong support for newborns aged 0-9 months.It also provides protection from injury for babies who are learning to walk. High-quality memory foam High-density and rebound-quality sponges can effectively protect your baby. Children sleep better and play safer on this mattress. Outer Cover & Inner cover The outer cover is removable and supports machine wash and hand wash. The inner cover can't be removed, which is designed to protect the mattress from dirt and keep it more firm, so make sure to long time using.