Fitted diapers have a contoured or form fitted shape and have gathered casings around the legs which provide great containment for even the loosest of contents. Some fitted diapers fasten with velcro & others with snaps. A waterproof diaper cover is necessary when using most fitted diapers, although many moms tell us they can go 2 hours at home without a cover - they often don't want to cover such cute prints! A new baby will need 10-12 fitted diapers & 6-8 diaper covers per day. Older babies & toddlers will need fewer fitted diapers and covers.