Ergo ZEN Clip unique "clip" mounting system; improved in-ear headphones and USB adapter are supplied in a package; supported audio formats: MP3 / WMA; shuffle playback mode; keyboard lockout; power from built-in battery; 2/4 GB internal memory; High-speed USB 2.0; Simple Plug&Play device; dimensions: 64 ? 21.8 ? 8.6 mm; supports Windows Vista, 2000, XP, and ME, MAC OS X or Never; player is available in black, red and silver. Memory type: Flash Built-in memory volume: 2, 4 GB Record formats: WMA, MP3 USB: Yes Power: from built-in battery Dimensions, mm: 64 ? 21.8 ? 8.6