Key benefits Flexible music playback from SD card or USB drive, allowing offline use without an internet connection. Portable power sourced from a user supplied TR18650 battery, enabling on the go use. Simple external speaker hookup with two wire cables, red for positive and black for negative, for easy wiring. Straightforward setup suitable for DIY audio projects, demonstrations, and portable sound solutions. What you need to know Battery: TR18650 battery is not included; the user provides it. Media sources: Insert an SD card with song files into the SD card slot or insert a USB flash drive with song files into the USB interface. Speaker connection: Twowire speaker hookup; red is positive and black is negative. How to use 1. Install the TR18650 battery first, paying attention to the positive and negative terminals. The battery is purchased separately by the user. 2. Insert an SD card with song files into the SD card slot, or insert a USB flash drive with song files into the USB interface. 3. Connect twowire speakers, red is positive and black is negative. 4. Power on and operate using your setup or the device controls to start playback. Use scenarios Outdoor events: power with a TR18650 battery, load a playlist on an SD card or USB drive, and connect external speakers for portable music. DIY audio projects: use as a playback module in a custom speaker system or prototype setup with external amplification. Classroom or meeting use: preload audio clips or songs on SD/USB media and play them with compatible external speakers in a small room.