Fitted diapers closely resemble disposable diapers. They are contoured and fitted with elastic around the legs and back. They fasten with Velcro or snaps and a waterproof cover must be worn over them. They are the next step up from flat pre-fold diapers and much easier to use. They may come with the absorbent lining attached or detached. You can add more liners/doublers to increase absorbency.