This is a baby helmet purchased on Rakuten. I no longer use it as my child can walk steadily, so I have stored it after home cleaning. I will give it to someone who will use it. Due to shipping costs, I will compress it for shipping. Normal size Standard diameter (inner): 48cm Minimum diameter (inner): 43cm Maximum diameter (inner): 55cm Height (inner): 10cm I am also selling other children's outgrown clothes. If you wish to purchase multiple items, please write in the comments beforehand, and I can offer a small discount as I can ship them together.