Hair accessories made from elastic can damage your hair by pulling at the follicles and fraying them. Hair accessories made from silk will do less damage but could slip, letting your style fall. Silk is also very hard to clean, leaving you with a dirty or wet hair tie. Hair accessories that do not damage your hair will be made from a unique TPU material. This material allows your hair tie to have a strong yet comfortable hold, just like the ones here at TELETIES. Best of all, they are BPA and phthalate-free!