Sai Aloha Water Shoes, Amphibious Size... Equivalent to 18cm I checked online and size XXS is equivalent to 18cm, but I recommend it for those who need a slightly smaller size. It was used a few times for water play and then stored. The logo has some peeling, so I've marked it as "slightly scratched or dirty" (images 5 and 6). Perfect for river and sea play! It will protect your child's feet from injuries. *Thank you for your understanding that this is a used item.