Blocks 99.99% of Wireless Signals Silver fiber lining blocks up to 99.99% of wireless signals from sources such as WiFi, 5G networks, and mobile devices. Built to GB/T 301422013 standards, it delivers reliable signalblocking performance without sacrificing comfort or style. Advanced EMF Signal Blocking Inner lining contains 35% pure silver fiber, significantly reducing electromagnetic field (EMF) exposure from smartphones, routers, and Bluetooth accessories. Designed for those looking to minimize daily contact with wireless radiation in a comfortable, wearable form. Comfortable for Daily Wear Soft organic cotton exterior with a smooth interior finish provides breathable, lightweight wear that is gentle on the skin, even for sensitive users. An adjustable fit and seamless construction ensure comfortable use from morning to night. Active Lifestyle Lightweight, breathable, and waterrepellent, this cap moves with you from workout to weekend—whether you're breaking a sweat or running errands. Use scenarios At work or on the go: use around routers and devices to reduce exposure while maintaining a casual, stylish look. Travel and commuting: keep EMF exposure lower in public spaces with wireless activity. Fitness and outdoor activities: wear during workouts or outdoor activities for breathable comfort with ongoing protection.