Sandisk SDMX18 4GB Red. Player media type: flash-media, Total storage capacity: 4 GB, Compatible memory cards: microSDTM/microSDHC. Display: OLED, Display diagonal: 25.4 mm (1 "). Equalizer modes: custom. Continuous audio playback time: 15 h. Dimensions (WxDxH): 54 x 15 x 34.5 mm, Media types supported: MP3, WMA, secure WMA, Audible, Ogg Vorbis, FLAC, Compatible operating systems: Windows XP SP2, Mac OS X 10.3