Sony PRS-300. Diagonal: 127 mm (5 "), Technology: Vizplex, Gray scale levels: 8 levels of grey. Document formats supported: bbeb, pdf, rtf. Interface type: USB 2.0. Battery life (max): 336 h, Battery technology: Lithium-Ion (Li-Ion), Battery voltage: DC 5.2/3.7 V. Minimum processor: 800 MHz, Minimum RAM: 512 MB, Minimum hard disk space: 20 MB