Dear Honey， for this item， there are 10 sizes for choice. Please check followlling:

if US 4， CN would be 35， fit feet length 22.5cm;
if US 5， CN would be 36， fit feet length 23.0cm;
if US 6， CN would be 37， fit feet length 23.5cm;
if US 7， CN would be 38， fit feet length 24.0cm;
if US 8， CN would be 39， fit feet length 24.5cm;
if US 9， CN would be 40， fit feet length 25.0cm;
if US 10， CN would be 41， fit feet length 25.5cm;
if US 11， CN would be 42， fit feet length 26.0cm;
if US 12， CN would be 43， fit feet length 26.5cm;

Noted: Above choices are all based on US Size， if you are European friend， Please choose the right size to place order. Thanks Honey