These skorts have a cotton outer layer with a bamboo inner layer with a middleTPU. They are great for wearing at bed instead of a waterproof wrap to give baby/child a break from leg elastic nappies or in the car on a long journey. They come in 2 sizes medium and large.Approx 0-4 years for medium and 3-10 for large. During tests large has fit upto a 32 inch hip.