Rubber material. The heel of Waffle 3.0 sole is mainly made of rubber. It is said that Ballman, the founder of the waffle sole, experimented with rubber, poured the liquid rubber mixture into the iron mold of his wife's waffle, and created the waffle sole, thus changing the design of the sports sole, hence the name. Waffle soles are favored by surfers and skateboarders for their excellent grip and wear resistance, good elasticity, comfortable wearing, wear resistance and water resistance, especially sandals and daily shoes, especially skateboarders.