The size is nominally 25.5cm, but it's quite large and roomy even for those who are a perfect fit at 26.5cm-27cm, so it's best to adjust with socks or insoles. They'll make you look taller, and they're top-class at it. I tried them on once, but they didn't suit me, so I immediately returned them and put them back in the box. I haven't had a chance to use them since, so I'm putting them up for sale. When paired with wide pants, they're completely hidden. They were stored in a smoke-free, pet-free environment, away from direct sunlight, where the humidity and temperature are consistently controlled throughout the year.