These BEANIES shield noggins from 99.9% of harmful EMF radiation*, while also being anti-bacterial, anti-static and anti-odor. BEANIES are stretchy and fit most heads. Stylish and comfortable: a much better look than tinfoil hats. *Testing was performed at a US test facility that is FCC Certified and NVLAP Accredited, where it was determined that the bubl shielding technology is effective at blocking 99.9% of the harmful frequencies emitted by Wi-Fi, 2G, 3G, 4G, and 5G mobile phone RF radiation, in addition to blocking 99.9% of the harmful radiation from computers, tablets, smart meters, power lines, Bluetooth and microwave ovens. bubl. Because we can't live in one.