Size ruler

Now all the hats have a drawstring, which will allow you to adjust the size to 1.5 cm. So there is your size less than 55 cm. This is not an obstacle at all.
All hats are unisex and are suitable for both men and women. So feel free when choosing both bright and restrained classic colors. The main thing that you like.

55 cm	S
56 cm	S
57 cm	M
58 cm	M
59 cm	L
60-61 cm	L
62 cm and more	L+