XL-ETFE, or Irradiation Cross-Linked Ethylene Tetrafluoroethylene, is a type of wire insulation used in aircraft and avionics applications. It is made by adding radiation crosslinking sensitizers, flame retardants, antioxidants, stabilizers, and other additives to ethylene-tetrafluoroethylene copolymer, and then undergoing a radiation crosslinking process. This technology imparts XL-ETFE with excellent flame retardancy, high and low-temperature resistance, chemical resistance, mechanical properties, aging resistance, and radiation resistance.