100% Cotton Flannel: Our pack n play fitted sheet for girls boys are made of 100% cotton flannel, this kind of fabric is ultra soft, warm, breathable and contains no substances, phthalates or chemicals which may harm your baby's skin or health. So it is more suitable for baby's delicate skin, providing your little ones a safe and comfy sleeping and playing environment. | Snug Fit: Stop worrying whether these pack n play sheets can fit your mattress pad, thanks to its thoughtful construction, 5” depth pocket, sewn with an elastic encased band help tightly secures the mattress pad in its place with no loose ends and zero bunching. Dimensions 39"X27"X 5". | Install In Seconds: Thanks to the elastic bottom ,those convertible mattress cover can be applied within seconds and guarantees to stay in place no matter what. | Easy Care: We recommend washing before first use. Due to the high shrinkage rate of pure cotton flannel fabric, the sheets you receive may feel a little big. It's recommended to wash before the first use, the sheets will fit perfectly. Machine washable on gentle cycle. Tumble dry on low heat or line dry. | Moonsea Guarantee: The product quality you can trust so you can buy at ease. If there is any problem with baby pack n play sheet, please contact us and we can replace for you or money back without excuses.