Papyre ebook 6.1. Diagonal: 152.4 mm (6 "), Technology: E Ink, Gray scale levels: 16 levels of grey. Document formats supported: CHM, DjVu, DOC, ePub, FB2, HTML, PDB, PDF, PRC, RTF, TXT, Audio formats supported: MP3, Image formats supported: BMP, GIF, JPG, PNG, TIF. Internal storage capacity: 0.450 GB, Compatible memory cards: SD, SDHC, Maximum memory card size: 16 GB. Interface type: USB 2.0, Headphone connectivity: 3.5 mm. Operating system installed: Linux