QQ-Tech 4th Gen 4GB IPX8 Waterproof MP3 Player for Swimming or other Sports (Green) USB File Transfer and Data Download; Support MP3/WMA format songs with USB 2.0 data transfer; Excellent design with perfect finish: ergonomic buttons control Forward/Back, Play/Pause, Volume Up/Volume Down allows ease-of-use, plus crystal clear sound; Unique Clip attaching to swimming and skiing googles,coolar and waist belt friendly; 100% Water-Resistant to a depth of 3-feet, designed for swimming and other sport activities; strictly built with International IPX-8 certification; No Shuffle; Built-in rechargeable Li-Polymer battery (3.7V, 200mAh) (Charge via USB); two and a half hours to charge; about 10 hours of continuous playing;