Generally, the skeleton inside the normal sole is a net structure, which will hollow out the deep body of the sole. If the solid rubber is heavy, it will affect the comfort of walking. Only when the sole touches the ground, the thickness of the body is not less than 6MM, the diameter of the keel reinforcement framework inside the sole is not less than 4MM, and the diameter of the cross cylinder support point of the heel framework is not less than 10mm, which are in line with international safety standards. Nowadays, the popular materials are lightweight. As long as the quality meets the above requirements, everyone likes to be comfortable and walk freely.