Upgraded Version of Tie-free and Wash-free Silicone Shoelaces for Adults (Colorful Black and White According to the needs of different groups the adult upgraded version finally comes into being under the development and improvement of the concerned staff This version is fitter for those whose vamps are wide and feet fatter It is easier to wear and more comfortable The shoelaces have strong overall tensile ability They are not easy to break and very comfortable to wear The colorful design meets the needs of different color matching Let your shoes cooler and more personalized Each shoelace is made of high-quality food-grade silicone and has super strong elasticity It can remain unharmed after 100,000 times of the tensile testing and will not break and fade even under the stronger stretching Besides the shoelaces are resistant to dirt and wash-free The unique fastener design can withstand greater The shoelaces are not easy to break or come out from the shoelace holes The silicone shoelaces use food-grade silica gel a kind of inorganic polymer colloid material polymerized by silicic acid Its main ingredient is SI02  NH20 whose content is above 98% It is non-toxic odorless and stable in chemical property Normally it does not react with any acid salt except the caustic alkali and hydrofluoric acid