【Elastic Knitted Material】Made of thick cotton and faux fur material, soft and comfortable. Can protect the forehead, chin, neck and ears, avoid frostbite with the detachable mask on the music beanie.【Detachable & Washable】Headphone can be taken off from the hat so that you can wash the hat.Therefore the icon panel on the hat is not fixed to the buttons. If the icons do not match the control buttons, please manually adjust them.【Built-in Microphone】The microphone in the music unisex hat makes it possible to transmit the speaking phone to your audio devices directly, hands-free answering.【Bluetooth Compatibility】V4.2 Bluetooth version, available for most of devices with Bluetooth function, wireless range up to 33 feet. Perfect for traveling, waiting for the bus, jogging in the cold or just rocking out in your bedroom.【Rechargeable Battery】The Bluetooth hat is equipped with a rechargeable 200MAH battery(Charge Time:2 Hours, Stand by time: 60 Hours, Working Time: about 4 hours).The battery board has a charging protection for the battery and can work while charging. (The red light will be on when charging, be off when charging is done).