It's 27.5cm. Since purchase, it has been stored in a zippered bag in the closet to protect against insects and moisture. This is a sold-out model from the Tokyo Olympics. The price will be gradually reduced from the current price setting on an irregular basis, so it's first-come, first-served. These shoes are highly recommended for those who want to improve their usual training, competitions, and records. I also have several pairs of different colors in the same size. If you're interested, please feel free to ask. Thank you for looking.