Welcome to the store! 1. APP Control: The stereo amplifier board supports mobile phone APP, Bluetooth, AUX, U-disk, USB sound card active speaker output, and passive speaker output. Bluetooth version is 5.1. 2. Stereo: The digital amplifier board connects via AUX audio, easily achieving stereo playback with 360-degree sound adjustment. Compatible speakers are 20W-200W 4Ω 8Ω. 3. U-Disk Mode: Connect the amplifier module to a U-disk, open the APP, and switch to "U-disk" mode. A prompt will appear to enter U-disk playback mode, restoring stereo sound. 4. Dual Channel: The audio amplifier board features left and right channel output interfaces. The 3.5 output interface can directly and effectively connect to passive and active audio devices or wired headphones simultaneously. 5. Support System: The stereo amplifier board supports Android and iOS systems. The APP offers visual operation for playback mode, volume, EQ, track control, play/pause, changing Bluetooth name, and setting connection passwords.