It's 27.5cm. Since I bought it, I've stored it in a zippered bag in the closet to protect it from insects and moisture. This is a discontinued model from the Tokyo Olympics. These shoes are highly recommended for those who want to improve their performance in daily training, competitions, and record-breaking attempts. The price will be gradually reduced from the current price setting on an irregular basis, so it's first-come, first-served. (This model is the last pair) Thank you for looking.