It is 2PCS,Waterproof 100% polyester PUL outer layer, designed for holding solids. | 100% nylon mesh inner for easy clean up and let the liquid freely flow through, offering comfort against baby's sensitive skin. | Interior polyester elastics at the waist and leg openings with soft lycra bindings provide a secure, stretchy fit and easy on and off. | Swim Diapers One Size Fit Baby 6-28 Pounds,Suitable for babies from birth up to 3 years old. | One size fits all: by adjusting the front corresponding snaps. Just perfect for saving your money in the long term.