10x6.25 which is a rebranded UC-Logic WP1062. It worked right out of the box on all the distros I tried so far, from what I recall it's supported through the xf86-input-evdev driver in the kernel. DIGImend is the main project behind getting better native support for the wide range of generic tablets out there. Probably best to check out their page if you want to know more about the specifics on the interface.
The main issue is that Qt doesn't support evdev properly yet and it has been an issue for a few years now, the most relevant bug report is here. MyPaint and Alchemy both worked properly without any configuration. GIMP and Inkscape needed to have the tablet enabled through their input devices interface; be aware that enabling the tablet will usually cause the mouse to get disabled simultaneously, so make sure to re-enable the mouse as well before saving and closing the dialog. I've heard that Blender has worked out its former issues with evdev as well, though I haven't bothered to try using it with it yet since the UI hasn't really taken tablets into account yet. To me it would be a pain to try to use the keyboard and tablet at the same time.
Overall I am really satisfied with the tablet; it's a great upgrade from the much smaller, less responsive and less sensitive Genius tablet I had before it. I've had it for nearly a year and a half now and I am still actually using the battery that came with it for the stylus and haven't had to replace the nib yet. Digital art is more of a part-time hobby for me though, so I don't use it nearly as much as some might which could account for how well those have been holding up.