Key benefits Portable music playback powered by a usersupplied TR18650 battery, enabling use away from mains power. Simple, reliable twowire speaker connection with clear polarity: red is positive, black is negative. Flexible music sources: play from an SD card or from a USB flash drive containing song files. Straightforward setup that minimizes wiring and keeps the system compact and easy to transport. What you need TR18650 battery (battery purchased separately). Twowire speakers or speaker cable. How to use 1. Install the TR18650 battery first, paying attention to correct polarity (positive and negative). The battery is not included and must be supplied by you. 2. Connect the speakers using a twowire link; red wire goes to positive, black wire goes to negative. 3. Insert a micro SD card with song files into the SD card slot, or insert a USB flash drive with song files into the USB interface. Compatibility and requirements Battery: TR18650 (user supplied). Speaker connection: twowire, with red as positive and black as negative. Music sources: SD card or USB flash drive containing music files. Use scenarios Outdoor gatherings and camping where portable power and simple wiring are advantageous. DIY audio projects or educational kits that require easy music playback from SD or USB sources. Small classroom or workshop environments needing a portable audio player for background music or announcements.