IREX Technologies Digital Reader 1000S. Diagonal: 259.1 mm (10.2 "), Technology: E-Ink, 768 x 1024, Gray scale levels: 16 levels of grey. Document formats supported: pdf, Image formats supported: JPEG, PNG, GIF, TIFF, BMP. Internal storage capacity: 1 GB, Compatible memory cards: SD. Interface type: USB 2.0. Battery life (max): 15 h, Battery technology: Nickel–Metal Hydride (NiMH)