[Advanced Technology]: Adopt silver plating technology, which has the characteristics of good toughness and strong shielding. Effectively against electromagnetic waves. [Washable]: The silver fiber protective cap can be washed by hand. It will not damage radiation protection, will not deform or fade. Note: Do not machine wash, bleach or dry clean. [Breathable Fabric]: This anti-radiation hat is made of 35%silverfiber,65%COTTON. It is soft, breathable, lightweight and well-made. [Satisfaction ]: I hope you will be satisfied with every purchase. If you are not satisfied with the product you ordered, just email your question to us and we will reply you within 24 hours. [Applicable people]: Shield the electromagnetic waves generated by computers, printers, photocopiers, microwave ovens and other electronic devices to meet people's radiation protection needs. People who often face computers and pregnant women.