Features: The bluetooth receiver is small and delicate, and features a USB interface that plugs directly into your home stereo system without requiring any external wiring. Users can easily play music from 10 meters away via wireless bluetooth transmission. It adopts the advanced bluetooth V5.1, so, data transfer rate have been raised to 2.1 Mbps that is three times as much as the current bluetooth technology, ensuring that the wireless audio transmission is more stable, in order to provide high quality sound and shorten the time of data transmission as well as reduce the power loss. Even if the user operates across the wall, he/she will operate freely. Newest technology allows the bluetooth receiver to pair with up to six devices, which solves the problem that the user has multiple bluetooth devices. The receiver is connected by USB interface and supports A2DP bluetooth stereo. Neither 3.5mm-to-rca nor 3.5mm-to-3.5mm audio cable is supported. It can be used on car and plays an important role in answering phone. With it, your stereo becomes a bluetooth stereo, based on that your stereo can play music via USB. Specification: Bluetooth: Bluetooth 5.1 A2DP V1.2: Support Output Interface: USB Audio Output Transmission Rate: 3 Mbps Transmission Distance: ≥ 10 meters / 32.8ft (without barrier) Power Supply: USB Power Supply Size: Approx. 6 * 1.9 * 0.7cm / 2.36 * 0.74 * 0.27inch Weight: 10.4g Type: Wireless Adapter Package List: 1 * USB Bluetooth Adater 1 * Manual .