PocketBook InkPad 4. Display diagonal: 19.8 cm (7.8"), Technology: E Ink Carta, Display resolution: 1404 x 1872 pixels. Document formats supported: PDF DRM, ACSM, AZW, AZW3, CBR, CBZ, CHM, DOC, DOCX, DjVu, EPUB DRM, FB2, FB2.ZIP, HTM, HTML, MOBI,..., Audio formats supported: M4A, M4B, MP3, OGG, Image formats supported: BMP, JPEG, PNG, TIFF. Internal storage capacity: 32 GB, RAM capacity: 1000 MB. Processor frequency: 1000 MHz. USB connector type: USB Type-C, Headphone connectivity: USB Type-C