The DefenderShield® EMF Radiation Protection Winter Beanie offers warm, comfortable, and stylish Electromagnetic Field (EMF) radiation protection for your head. Made with high-quality acrylic yarn and EMF silver shielding, the DefenderShield Winter EMF Beanie can be worn day or night to keep your head warm and help shield yourself from ambient EMF emissions in the environment or EMF radiation emitting from your devices. Perfect For: travel, sleep, on-the-go, winter activities, dense EMF environments. Advanced shielding blocks 99% of wireless Radio Frequency (RF) EMF radiation and 5th Generation radiation (300 Hz-10 GHz).