The device supports PDF and ePub formats, but it seems to be geared toward writing and drawing as much as reading. It has a 10.3-inch E Ink screen with a resolution of 1872 x 1404 (226 ppi). It features a capacitive touchscreen and a Wacom-based touchscreen to use a stylus pen that supports 2048 levels of pressure sensitivity.
Pre-orders are currently available from the reMarkable website for $479.
What is "remarkable" is that it is much cheaper than the 13.3" Sony DPT-RP1 which has no ePub support.