First, the main function: 1. Music format: MP3 / WMA / WAV / FLAC / APE lossless format music. 2, AC5322B Bluetooth version is version 5.0 3, 2 x 3W, connect 2 3W speakers. 4, support TF card, support USB interface (U disk); 5, power failure memory function; 6, support 5-10 meters distance infrared remote control operation; 7, support external audio input LINE IN (AUX); 8, support radio FM, receiving frequency band (87.5MHZ-108.0MHZ); 9, button: four buttons multi-directional control, the previous song / play pause / next song / MODE; 10, support MP3 / USB / TF / LINE IN / FM / BLUETOOTH / DC 5V; 11, on the structure: panel size: 85 x 32 MM, the depth of the board is 33 MM Second, the button operation details: 1. VOL-button (previous song/volume reduction): In MP3 state, VOL-short is the previous song, long is for volume reduction; in FM state, short to adjust one station number; in Bluetooth Short under the function is the last song of Bluetooth, long to decrease the volume. 2. AUTO button (play/pause): In the MP3 state, AUTO is short pressed to play/pause; in FM state, short is play/pause, long is for automatic receiving and saving; in Bluetooth function, short to play /. VOL + button ( song / volume increase): In the MP3 state, VOL + short for song, long for the volume to increase; short in the FM state to adjust a station number; under the Bluetooth function Short for song of Bluetooth, long for the volume to decrease. MODE button: switch between USB/SD/FM/AUX/Bluetooth function. External Memory: Yes Balanced Out: No : AC5322B Function: FM Radio Function: bluetooth Function: Build in Speaker Package: No Style: Car MP3 Supports FM: Yes Operation Mode: Contact Screen + Remote Control Storage Type: Flash Memory Signal Noise Ratio: 3dB Battery Life: 20 hours Dimensions (WxHxD): 85 x 32 x 33MM Supports Recording Function: Yes Display Size: None Model Number: MP3 Decoder Board Audio Module Bluetooth: Yes Have Speakers or not: Yes Battery Specification: External Power Supports EBook Reading: No WIFI: No Colour: Black Material: ABS Screen: No Function introduction: support Bluetooth function / with amplifier 2 x 3W / double decoding MP3, WMA, WAV format music / read USB disk / read TF card / radio FM / external audio input LINE IN (AUX) / infrared remote control / power off memory / Power supply 5V Package Contents: 4 x MP3 Decoder 16 x 2P Cable 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.