Material:100% silver fiber (anti - radiation material) Size: Suitable for head circumference: 50cm/54cm Package including: 1Pcs hatPlease note that this model can be worn separately as a hat or sewn into the hat as an inner liner Function: 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 wirele network modems and routers, Bluetooth devices, smart meters, cell phone towers, mobile phones, microwave ovens, wirele phones and security systems; 3. Reduce the radiation generated by low-frequency electric fields such as wires, electric boxes, household appliances and high-power transmiion lines; 4. Effectively protect the head Features : 1. Using nano silver fiber worsted spinning technology, good shielding performance, light and thin material, good ventilation effect! 2. Washable, resistant to abrasion and washing 3. It is a kind of green product fabric as a protective material suitable for civilian use. 4. Anti-radiation, eliminate static electricity, and can be worn personally. Washing method: 1. The radiation protection suit can be washed directly with water, and ordinary neutral detergent powder and detergent can be used. The washing method is similar to the cleaning proce of ordinary clothes; 2. Wash the radiation protection suit by hand gently, try not to use the washing machine; 3. Don't twist it after washing, just pick it up from the water and dry it; 4. The water temperature should not exceed 90 degrees; 5. Ironing at medium temperature, the temperature does not exceed 150 degrees; [NOTE]: Cell phone signal does not equal cell phone radiation The mobile phone signal is a high-frequency microwave signal. It is the ability of the mobile phone itself to receive signals. It is basically harmle to the human body. The mobile phone signal has spread all over the world and is also supported by the countries of the world. The mobile phone can automatically search for signals. The steel in high-rise buildings is all steel. The elevator can receive signals, so the mobile phone initiative to search for signals has its own particularity. The protective effect of radiation protection knitted hats can't be based on the strength of mobile phone signals. My anti-radiation knitted hats are protected against electromagnetic waves generated by the sudden increase or decay of electric currents in electronic components, and are not anti-cell-phone signals.