Material:Outer material: 100% cottonLining: 100% silver fiber (anti - radiation material).Size: Suitable for head circumference: 50-60cmFunction:1. It is used for shielding and protection of electromagnetic radiation, suitable for various places with radiation;2. Reduce the radiation generated by high-frequency radio frequency electromotive force of wireless network modems and routers, Bluetooth devices, smart meters, cell phone towers, mobile phones, microwave ovens, wireless phones and security systems;3. Reduce the radiation generated by low-frequency electric fields such as wires, electric boxes, household appliances and high-power transmission lines;4. Effectively protect the headPackage including: 1pc