1)100%silicon are available here. 2)comfortable wearing 3)waterproof The specifications of rubber key tag:the certifications passed:ISO14001,ISO9001,ROHS,REAH,UL,FDA,etcthe advantages of the products are as follows:1) heat resistance2) cold resistance3) abrasion resistance4) water proof5) good quality6) best serviceif you want to know more about us,pl be free to contact us!