Specification: 1. 24-bit DAC output, dynamic range support: 90dB, signal-to-noise ratio support: 85dB 2. It fully supports FAT16 and FAT32 file systems, it is a TF card that supports 32G, a U disk of 32G, and NORFLASH of 64M bytes. 3. The broadcast language interrupt function, you can pause the background music being played. After the ad is played, return to the background sound to continue playing 4. The audio data is sorted by folder, which supports 100 folders, and 255 tracks can be assigned to every folder 5. 30 levels of volume adjustable, 6 levels of EQ adjustable application: 1. Voice prompts for road transport inspections and toll stations 2. Voice prompts for inspection at railway stations and bus stations 3. Voice prompts for power, communications, and financial business halls 4. Voice prompts for vehicle entry and exit channel verification 5. Voice prompt for border inspection channel 6. Multi-channel voice alarm or equipment operation guidance voice 7. Voice notice of electric sightseeing car 8. Automatic alarm for mechanical and electrical equipment failure Specification: 3pcs *DFPlayer Mini MP3 Player Module DFPlayer Mini is an MP3 module that can be directly connected to speakers. The module can be used alone with the power supply battery, speaker, and buttons, or can be controlled via serial port, as a module of Arduino UNO or any single-chip microcomputer with serial port The module itself integrates hard decoding of MP3, WAV, and WMA. At the same time, the software supports TF card drive and supports FAT16 and FAT32 file systems. Control mode: I/O control mode, serial port mode, AD button control mode. Support sampling rate (KHz): 8/11.025/12/16/22.05/24/32/44.1/48. Application: Car navigation voice broadcast, fire voice alarm prompt, automatic broadcast equipment, regular broadcast