Not only 220V charging dock included, but also DC connector supports 12V / 24V charging; Selects 2200mAh lithium battery, longer standby time; Clear sound and excellent performance; Long distance transmission; Wearing-resistant PC material, durable and reliable; Communication signals can reach about 10km in plain area, 5km in open moutain and forest area, 2~3km in buildings of city area; Lots of factors will influence and interfere the wireless, but it can be enhanced by adjusting the azimuth or modified power and antenna.