Specifications:<br />Type: Bluetooth Headset<br />Model: V18<br />Bluetooth version: BT4.0<br />Built in one battery: Type 401 025 Class A + 75 mAh batteries<br />Charging voltage: DC5V 150 mAh<br />Transmission frequency: 2.4 GHz-2.48 GHz<br />Transmission distance: 10 meters<br />Working Current: 25-35mA<br />Output power: 35 mW<br />Distortion factor:   $ number<br />Frequency response: 20Hz-20KHz<br />Working Time: Music 4-6 hours (Volume will affect time)<br />Charging time: 1 h-2 h<br />Sensitivity: 85dB<br />Impedance: 32 ohm<br />Package Size: Approx. 9.5 * 7 * 3 cm / 3.7 * 2.8 * 1.2in (L * W * H)<br />Package weight: Approx. 44g / 1.5oz<br /><br />Package list:<br />1 * Headset<br />1 * USB cable<br />2 * Gel Pads<br />1 * User Manual (English)