The Koss MP3 TUGO is a completely self-contained MP3 headphone. Tugo contains MP3 software and circuitry that allows easy downloads from your laptop or PC. Incorporating a 512 MB memory, the Tugo provides uninterrupted listening for 8-15 hours. Tugo comes with a mini USB input jack that interfaces with your laptop or PC for file sharing and by operating on a built-in rechargeable Lithium ion battery, Tugo can recharge off your laptop or PC in 3 hours or less. Tugo folds flat in a streamlined carrying case for protective storage and is covered under Koss No *Questions* Asked Lifetime Warranty.