Rubber Leisure Products' Bubble Cap is made from superior quality natural rubber. This cap is specially design with soft air bubbles with three dimensional in shape, therefore fits well and comfortably on swimmer heads. The special production process makes the surface of the cap silky smooth and does not pull the hair when removing or putting on cap. It is well-suite to swimming in colder conditions because of its heavy-weight rubber, air bubbles insulation and crepe bubbles which keep swimmers warm.