Please make sure to confirm the size before purchasing.Not every pair of shoes is in standard sizes.The inner length of the shoes is measured manually, and there may be a reasonable error of about 0.5cm Regarding the selection of children's shoe sizes, please note the following: Most children's shoe sizes are based on manufacturer's standards and do not have a unified standard (different shoes of the same size may have different dimensions). Please measure the foot length. For summer models, it is recommended that foot length + 0.5cm = shoe inner length. For spring/autumn and winter models, it is recommended that foot length + 1cm = shoe inner length (the cm indicated after each size is the shoe's inner length) Size 21 inner length is 13cm cm. Size 22 inner length is 13.5cm cm. Size 23 inner length is 14cm cm. Size 24 inner length is 14.5cm cm. Size 25 inner length is 15cm cm. Size 26 inner length is 16cm cm. Size 27 inner length is 16.5cm cm. Size 28 inner length is 17cm cm. Size 29 inner length is 17.5cm cm. Size 30 inner length is 18 cm. Recommended foot length +1 cm = shoe inner length Fleece-lined version