The Waterproof Cotton Protector is 100% waterproof so protects baby's mattress. Machine washable and tumble dry on low, keeps it 'always clean and hygienic' and ready to use. Made from cotton fabric with an inner PU lining, the mattress protector resists liquid water passing through. No need to worry if they wet the bed; this mattress protector will surely keep your baby sleeping comfortable without irritations.