To supply warmth, poly or cotton batting is inside, but you can also skip it.
A tab on one side protects your child from being injured by the slider head of the zipper.
The zipper is safe and its installation is very simple.
XS: newborn – birth
S: 3 mths
M: 6-9 mths
L: 12 mths – 18 mths
XL: 18 mths – 2 years
XXL: 3-4 years