Features 1、Professional Design: Bluetooth receive or transmit mode and optical coaxial digital to analog conversion. u disk AUX sound input, multi device expansion interface, to meet different needs. 2、Plug and Play: Connect old speakers or amplifiers AUX RCA interface, solve the problem of speakers without Bluetooth, can not use Bluetooth playback, support U disk playback, driver‑free, plug and play. 3、HiFi Lossless Sound: Bluetooth receiver transmitter with HIFI shock lossless level sound quality, clear and noiseless, enjoy good music, natural good mood, support format MP3 APE FLAC WAV WMA. 4、Bluetooth 5.1: Bluetooth aux adapter uses Bluetooth 5.1 chip, transmission signal stability, low latency and high restoration of sound signals in the wireless transmission, hifi sound data restoration, enjoy the sound quality of wired connection in the wireless connection. 5、Long Range: Bluetooth transmitting and receiving without pressure, 30M unobstructed stable transmission, music without delay, strong signal, so that the room connection without dead ends. Specification Item Type: Bluetooth Receiver Transmitter Material: Aluminum Alloy Remote Control Battery Type: Built In 160mAh CR2025 Button Cell (Included) Bluetooth Version: Barrier Free 30m/98.4ft Interface Type: Optical, Coaxial, Aux, RCA, USB Interface Bluetooth Protocol Support: A2DP and AVRCP Music Format: MP3 APE FLAC WAV WMA Package List 1 x Receiving Transmitter 1 x Fiber Optic Cable 1 x Sound Line 1 x Power Supply Line 1 x Remote Control 1 x Instruction Manual