Sony SRS-T33 Compact Portable Speakers (Blue) Single chassis, dual speakers with 1 watt per channel x 2 Compact, foldable design permits easy transport wherever you take your portable music player or digital voice recorder 1.3-inch neodymium-magnet drivers produce high energy output for greater speaker movement, power, and sonic accuracy Magnetically shielded so the speakers will not disturb images when close to a TV or monitor Works for 24 hours on DC (Battery 2xAAA)(not included); also works as a passive system driven by your portable device (no power required)