Such a cute bonnet, made with cotton fabric.
Sizes are are approximate to the age of your child
The straps will be thicker than shown.
 
Size guide
Age                  Child's head
Newborn           13.75"
0-3 months       15"
3-6 months       17"
6-12 months     18.25"
1-3 years          19.5"
3-5 years          20.5"
5+ years -         21.5"