AudioTechnica AT-SP21 Folding Compact Portable Speakers (Discontinued by Manufacturer) Foldable lightweight compact design Does not require batteries or AC connection Large aperture 40mm speaker unit with powerful bass Compact speaker system for MP3 players and other audio devices with a 3.5 mm headphone jack Sleek, lightweight design with thin profile for easy transport No batteries required Hassle-free solution for travel Ultra-portable, quality sound