1. 3.3-5.2VDC power supply, recommended to use 3.7V and above power supply. 2. Support MP3, WAV decoding format, support for audio files with a maximum sampling rate of 48KHz. 3. Support UART asynchronous serial port control, support play, pause, up and down song, volume up and down, EQ mode switching, select song playback, specify the path to play, specify the path to interrupt playback and other functions. 4. With 5W Class D amplifier, can directly drive 3W-5W speakers. 5. Support TF card (memory card), U disk; capacity of 32G or less, FAT32 format. Support customized audio files. CX-ST5B is a compact serial port (UART) control voice playback module, supports MP3, WAV decoding format.3.3-5.2VDC wide voltage power supply, direct-drive 4-8Ω speakers, the maximum output power of 5W.Supports TF card, U disk, connect to the computer to replace the audio file through the USB cable, suitable for many scenarios of applications. Due to different batches, there may be differences in product appearance and printed text, which will not affect use Color: black Material: PCB Package Contents: 1 x CX-ST5B module 1 x Speaker 1 x CX-340 module 1 x Data cable (cable color in the picture is random; data cable Random Color, don't accept the specified color) 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.