Product Overview: It is a Bluetooth transmitter and receiver in one model. When you use it as a Bluetooth transmitter, it sends the audio signal to your Bluetooth receiver device such as Bluetooth headphone or Bluetooth speaker etc. via Bluetooth technology. When it worked as receiver, it works as a stereo Bluetooth speaker (plug the 3.5mm cable into 3.5mm Aux socket) to get the audio signal via wireless transmission. The latest Bluetooth 4.1 technology with APT-X technologyThe latest Bluetooth 4.1: bring a broader range of reception launching, lower power consumption, better compatibility. APT-X technology is supported. Dual link support: It can connect two Bluetooth devices simultaneously as a Bluetooth transmitter or receiver (but as receiver it does not play music from two mobile phone at the same time, but you can choose any mobile phone to play music. You need to pause or end the music from one mobile to play the music from the other mobile phone). As a transmitter, it will send to two devices simultaneously at the same time.Using while charging: you can use the unit while charging. Excellent Battery Performance: It provides up to 12 hours working time with single connected device. It takes 2 hours to charge the battery full.