I bought these so they would be easy to spot at sports day, and my child wore them once a year (from 1st to 4th grade). It's hard to tell from the photos, but the colors other than light blue are fluorescent. The size is probably around 15cm to 17cm. They could still be worn, even when my child's feet were 20cm. To make them easier to find, I had my child wear mismatched shoes, so one of them is dirty. Only the light blue one is unused. These are used items, so please understand before purchasing. Thank you very much.