1800 is what the community calls a keyboard layout/form-factor similar to the one of the Cherry G80-1800 keyboards. It is increasingly being used by other brands, and in runs of custom keyboards.
The alphanumeric section and numeric keypad are placed next to each other with only a small gap. The arrow keys have been squished in-between them and the nav cluster has been relocated elsewhere or omitted entirely.
Keys around the arrow keys are often shrunk or displaced to make everything fit.