The soft and stretchable material maintains health to the greatest extent.The 2-in-1 design makes it easier to connect with wireless Bluetooth headsets, so you can listen to your favorite , answer calls or hang up hands-free.The LED light on the hat provides great in the dark environment.Built-in rechargeable battery, which can be by USB cable, and it has long standby time.Perfect for outdoor hiking, jogging, skating, biking, dog walking, winter , etc.Colour:blackMaterial:Acrylic fiberSize:about 20 x 23cmPackage Contents:1 x Bluetooth capOnly the above package content, other are not included.Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.