This SIO diaper is a basic insert that you can combine in different ways: with a classic Petit Lulu waterproof cover (NOT included), for example, it immediately transforms into an ALL – IN – TWO. You can start using it immediately after birth and it will be sufficient for the first 6 months or so. If you need to increase absorbency, you can easily combine it with other inserts (long or short) or purchase the NEW Petit Lulu inserts with button separately. This new version has a particular cut, which narrows at the back thus ensuring little bulk and great freedom of movement. Thanks to the material used (bamboo terry), the level of absorbency remains high. It's perfect for daytime wear. It can be machine washed and dries easily. The small elasticated wings around the legs protect the outside from any pee spills. legs protect the outside from any pee spills. It is composed of 60% bamboo viscose and 40% organic cotton (4 layers).