Features: Realize the two-in-one design of BT5.4 Auditory receiving and transmitting function, which is convenient for users to transmit Auditory signals wirelessly between the car stereo and other devices. Adopts BT5.4 technology, stable and fast transmission; Supports a variety of Auditory formats, such as MP3, WAV and so on; Built-in highly performances chip to ensures clear sound quality; compact and portable, easy to carry and use Connect your cellphones or tablets PC with the car stereo in your vehicle to play music wirelessly; Convert corded stereo to stereo, easy to connect with wirelessed devices; Specifications: Size:about 54x54x15mm/2.13x2.13x0.59in Adopt：BT5.4 Package Includes: 1PC AUX Auditory Transmitter Receiver note: Due to the problem of lighting effect and shooting, there might be tolerances in product, please understand. Please allow 0-1cm error due to the measurement