Children's shoes that can change size according to growth

Shoes that corresponded to children with fast growth by pushing buttons to extend and contract. With these shoes, you can hardly wear it and the size will not fit and you may not want to replace it many times.

Will not you make something for children growing like this?

Details are as below.
The first size is 11.


Push the button next to the shoe and pull it to size 12.


There are also boots.


A movie that picked up these shoes at CNN.
YouTube - Inchworm Shoes


The official site is here. There are various sizes and kinds, price is from 19.95 dollars (about 2400 yen). You can see a movie introducing shoes from PRESS.
Inchworm Shoes Online