3cm. According to relevant public information, compared with 5cm, 3 cm heel is safer and more comfortable to wear, and the curve is more in line with the skeleton structure and mechanical stress principle of human foot. If it is too high, it will hurt your ankle. Inner heightening leather shoes are a kind of ordinary shoes. Ingenious design, combined with heightening high floors, can immediately achieve the same heightening effect as wearing high heels, but they are very close to ordinary shoes in appearance, so some people call heightening shoes invisible heightening shoes.