AUX interface: receiving/transmitting dual mode, AUX interface, widely compatible, support all audio equipment, Functional: Convert wired devices into Bluetooth-compatible signals and send them to Bluetooth-compatible devices for output wirelessly Convenient: Connect 3.5mm audio, so that ordinary speakers can also play wireless Rechargeable Battery: Large capacity battery, lasting a whole day, built-in 200mAh large capacity rechargeable lithium battery, support charging while working Sound Quality: 5.1 "Powerful" movement, bluetooth-compatible 5.1 version, provides high quality wireless audio performance Car Use: Let the old car stereo upgrade car bluetooth-compatible audio, mobile phone easily connected car audio, wireless music/navigation Product function: receive + transmit + call 3 in 1 size:about 80x20mm Material:ABS colour:Black Package Contents: 1 x Bluetooth-compatible Receiver 1 x charging cable 2 x audio cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.