This Panasonic Travel Speakers (Active Speaker System) is handy for your travels with approximately 8 hours play time (manganese) battery, or approximately 21 hours on (alkaline) batteries. They are a slim compact unit and easy to fit in case and carry around, enabling you to listen music from your iPod and MP3 player with high quality at anywhere you like. The 3.5mm universal headphone jack allows you to plug into other music devices.