These cable ties are made from a heavy duty grade nylon called Polyamide 6.6, or Nylon 66. Quick and secure to use, with a slight angle to the pointed end to ease insertion into the head of the tie. The internal teeth on each cable tie provide for a very secure fix, whether you use them purely by hand or with a tensioning tool. Our ties are weather-resistant, UL Approved, and their self-extinguishing properties make them very fire retardant as well. Polyamide 6.6 is Halogen and silicon free, so we didn’t forget to stay environmentally friendly.