1,Foldable 2, Bluetooth 2.1 wireless 3, High quality Products descriptionBluetooth wireless headsetSupport systems:audio equipments with bluetooth functions,such as PC,cellphone,MP3…Bluetooth standards: Bluetooth V2.1+EDRReceiver range:10m / 360.Carrier frequency:2402MHz-2480MHzUSB interference:High speed USB 2.0Battery:rechargeable lithium-ion polymer battery (3.7V/320MA/h)Successive working ...