Diver 4GB Waterproof MP3 Player with LCD Display and Earphones (Blue) Now with swimometer to track your strokes during swimming. Compatible with Win 2000/Win XP/Vista/Win 7/MAC OS X. Easy USB 2.0 Interface. Plays MP3 & WMA Format Files. Built-in FM Radio Audio. Net player weight only 21 grams (Not Including Earphones). Includes one set of waterproof earphones. Built-In Li-ion Battery.