Age group
The recommended age range for kangaroos/slings is somewhat arbitrary, as children of the same age can vary in weight, height, and development. However, it provides a rough estimate of how suitable a particular model may be for your baby at different stages. The lower age limit, though, is more strict; for instance, if a backpack is labeled "3-12 months," it shouldn't be used for newborns as it's not designed for their needs and could potentially harm their bodies.
Now on the market are carriers designed for this age:
from birth,
from 3 months,
from 6 months.
Height adjustment
Ability
to adjust the height of the baby in the sling/kangaroo. This feature provides the ability to adjust the device for maximum comfort for both the baby and the mother. And in some models due to the adjustment can also change the internal volume, which can be useful as the baby grows.
Bib
The presence of a
bib in the delivery set of kangaroo/sling. Unlike the classic use (when the bib is attached to the child's chest and protects his/her clothes from contamination), in this case it is attached at the level of the baby's head and covers the parent's clothes. A very useful feature when carrying the baby facing the mother (see "Orientation").
Back pocket
The presence of a
pocket on the outside; commonly found in kangaroo backpacks. This pocket can be used to transport a variety of additional items, ranging from toys and baby food jars to documents and other personal items.