QQ-Tech&reg; 4GB Waterproof MP3 Player With FM Radio for Swimming Surfing SPA IPX8 (Black) Good for most sports, specially designed MP3 player for swimming, spa, and other water sports Excellent waterproof performance complying with International Standard IPX7 Built-in 4G memory, comes with waterproof earphones Rechargeable Battery each time last for 8-12 hours; Systems: Windows 98SE/ME/2000/XP/Vista/Win7, Mac OS 8.6; Music format: MP3, WMA