Fangrui Product Details 1. Bluetooth Audio Receiver, Supports Aux/optical/coaxial Interface/u Disk/tf Card/microphone Rich Interface, Nfc Close Connection, Wireless Remote Control, Hifi Lossless Sound Quality, Bluetooth V5.3 Plug And Play Driver 2. The Old-fashioned Power Amplifier Instantly Has Bluetooth Function And Supports Optical Fiber Coaxial Port Output To The Power Amplifier Device To Experience The Fun Of Wireless Music. 3. The For Original Sound With One Click And Sing Clearly Without Any Whistling. 4. Rich Interfaces And Expanded Connections To Meet Different Devices, Supporting Aux/optical/coaxial Simultaneous Audio Output 5. Listen To High-quality Songs Without Delay, Restore High-fidelity Stereo Sound Quality, Stable Transmission Via Bluetooth 5.3, Plug-and-play Usb Flash Drive Bluetooth Version:v5.3 Audio Decoding: Bluetooth Protocol Support:a2dp/avrcp File Format:mp3/wav/wma/flac/ape Frequency Range:2400mhz-2483.5mhz Frequency Response:20hz-20khz Output Load:16-320ohm Adaptive Transmission Distance:10-30m (open