The size is nominally 25.5cm, but it's quite large and roomy, so it's best to adjust with socks or insoles. It'll make you look taller, the best in its class. I tried it on once, but it didn't suit me, so I immediately went back and put it back in the box. I haven't had a chance to use it since, so I'm putting it up for sale. When paired with wide pants, it's completely hidden. It was stored in a place where the humidity and temperature are consistently controlled throughout the year, away from direct sunlight, in a smoke-free and pet-free environment. Color: Black