It is flexible and fits to massage the soles of the feet. It rubs against each other while walking, and plays a role in massaging the soles of the feet.Soft and comfortable, comfortable to wear,loofah insoles, even if the sweat is more, the surface is dry. Feature - Color: As shown. - Material: Loofah. - Size 36: About 23cm(length of insole); 7.5cm(insole head); 5.8cm(insole tail). - Size 37: About 23.5cm(length of insole); 8cm(insole head); 6cm(insole tail). - Size 38: About 24cm(length of insole); 8.5cm(insole head); 6.2cm(insole tail). - Size 39: About 24.5cm(length of insole); 8.5cm(insole head); 6.3cm(insole tail). - Size 40: About 25cm(length of insole); 8.8cm(insole head); 6.3cm(insole tail). - Size 41: About 25.5cm(length of insole); 8.8cm(insole head);6.3cm(insole tail). - Size 42: About 26cm(length of insole); 9cm(insole head); 6.7cm(insole tail). - Size 43: About 26.5cm(length of insole); 9cm(insole head); 6.7cm(insole tail). - Size 44: About 27cm(length of insole); 9.5cm(insole head); 7cm(insole tail). - They can protect against pressure to your forefoot touching the ground directly and relieve the fatigue efficiently. - and comfortable material can effectively reduce feet pressure and fatigue. - The insole is breathable and sweat-absorbent which can keep your feet dry and clean. - Exquisite suture craft make it more comfortable and not easy to break. - Relieve feet fatigue and odor, make feet skin healthy and bright.