Description: sound quality. Onboard 2W mono amplifier (5V power of up to 3W) is directly connected to the speaker (recommendation 4 3W speakers), 3.5mm gold plated headphone can connect with headphones or external audio. With a Micro USB port. Through the mobile phone data line can use mobile power supply or the USB cable to charge, also can use 3.7V lithium battery, or USB 5V power supply. Support TF Card (mobile phone memory card) and U disk play . No soldering with speaker terminals for easy wiring. The module is designed to facilitate modification. Specification: Power range: 3.7-5.5V Support MP3 format, playing power on automatically. When mp3 is played the red LED flashes. Support U disk (test 32G), TF Card (test 16G) play ; power on default TF card , if the TF card does not exist automatically jump to the U disk , and both devices have installed, then you can manually set the play . Buttons can be adjusted up and down to control songs,volume up and down, pause or play, switching. Press menu button enter the single/all song play . The default is the all song when power on. Pressing the Repeat button can replace the circulating . Key Operating Instructions: "Prev / V--" button: "Press" for switching previous song, "long press" for volume down. "Next/v++" button: "Press" for switching next song, "long press" for volume up. "P / P / " button: "Press" for the "Play/Pause" Switch, "long press" for U disk, TF card . "Repeat" button: "Press" for "single/all song" (no long press). Package Includes: 1 x MP3 Decoding Board