Description : Face Covering High Elastic Silver Fabric Keep Warm Neck in Winter and Effectively Block Electromagnetic Waves Shielding Efficiency:With 99.9% shielding efficiency. The fabric is 100% silver fabric, while some of our competitors use less than 50% silver fabric Wearing Method:It can be worn as a headband, neck gaiter, face mask, sunscreen, headband or balaclava The leggings are highly elastic and very comfortable to wear Protective Effects: protect the most important parts of your neck . How to test: Don't put your phone inside and try to make a call. This is not an accurate way to test validity Instead, use an EMF meter to compare RF/microwave levels inside and outside the device |