Hanvon WISEreader N610. Diagonal: 152.4 mm (6 "), Technology: E Ink, Gray scale levels: 16 levels of grey. Document formats supported: pdf, epub, Audio formats supported: MP3, WMA, WAV, Image formats supported: JPG, PNG, GIF, TIF, BMP. Internal storage capacity: 4 GB, Compatible memory cards: microSD, Maximum memory card size: 32 GB. Interface type: USB 2.0, Microphone connectivity: 3.5 mm. Operating system installed: Windows CE 5.0