1.stereo bluetooth receiver 2.built-in rechargeable battery 3.simple design,compact size 4.one button control portable ... , iPad, cellphones, laptop etc*One button control*With built-in rechargeable battery, for portable use*Compatible with Bluetooth V1.1, V1.2 ... door), or 20 Meters(outdoor)*Battery type: Li-ion, 3.7V, 150 mAh*Battery working time: 5 hours*Battery charging time: 2.5 hours ...