Sandisk 1GB Sansa M240 MP3 Player w/ Portable Speaker Dock (SDMX3SPD-1024-A40, Retail Package) Compact speaker system designed for select Sansa MP3 players Built-in dock holds and charges e100 and m200 series models 3.5 mm auxiliary input connects to other MP3 players or CD players Runs on 4 AA batteries (not included) or AC power USB connection for direct music downloads; 1-year warranty