Material: Ultra-soft acrylic blend with excellent insulation. One size fits men, women, and children. Features: Unisex knitted LED Bluetooth beanie with 4 built-in and removable rechargeable LED lights. 10 hours of battery life, offers a standard USB port to charge the battery, you can charge it in a car charger, computer, or power bank portable power supply, never buy batteries again. The longest operating time on the market: The Bluetooth beanie with a built-in 300mAh rechargeable lithium-ion battery can work for about 8 hours of working time, talk time, and 6 hours of playtime, while other brands only have 120 mAh and 1-2 hours of playtime. Unisex, Washable, Thick Knit: Lightweight, removable, cool to the touch, fully washable, stretchy, suitable for all sizes and shapes, has 3 brightness settings. USB rechargeable batteries included. Unique Gifts for Men and Women: Upgrade Bluetooth mobile phone function to the latest Bluetooth V4.2 technology and sync them with any Bluetooth device in seconds, hands-free connection, including rejecting/receiving calls, listening to music wirelessly, up to 33 feet (10 meters) stay warm in winter. Best Christmas gift.