Sony PRS-T1. Diagonal: 152.4 mm (6 "), Technology: E Ink Pearl, Gray scale levels: 16 levels of grey. Document formats supported: ePub, PDF, TXT, Audio formats supported: AAC, MP3, Image formats supported: JPG, PNG, GIF, BMP. Internal storage capacity: 2 GB, Compatible memory cards: microSD, SD. Interface type: USB 2.0, Headphone connectivity: 3.5 mm, Wireless LAN type: 802.11b, 802.11g, 802.11n. Battery technology: Lithium-Ion (Li-Ion), Battery voltage: 3.7 V