Specification: Type: Bluetooth Audio ReceiverMaterial: PlasticQuantity: 1 pcItem Color: BlackBluetooth Version: 4.1Frequency Range :2.4GHzProfile: A2DPTransmission Range: Up to 10m / 33ftI/O 3.5mm female plug, Mini USB female portPower Supply: DC 5VCharge Time: About 30 minWorking Time: About 4hSize: 1.4*1.5*5.8cm / 0.5*0.6*2.3" (L*W*H) Package: 1*Bluetooth audio receiver1*3.5mm to 3.5mm adapter1*English user manual