17cm I'm selling these because the size didn't fit after I bought them two months ago. I put my name stamp on the part shown in photo 6. The stamp has been wiped off and is faint, but it's still visible if you look closely, so please only purchase if you don't mind. The non-slip grip on the bottom is still good, so they seem very easy to wear ^ ^ They will be shipped without the box. They have been home cleaned, but there are some scratches and stains. Please understand that these are used items and only purchase if you are okay with that. ✳︎