This is the Seiko UC-2000 shown with the Seiko UC-2200 terminal

The UC-2000 is a watch, it shows the time, lives on your wrist

But most importantly, it could be combined with the UC-2200 terminal to make a reasonably well featured personal computer

The watch face served as the screen of the whole system which also had a spool-fed printer, 4K of RAM and 26K of ROM on a removable cartridge

You could make your own applications for it in BASIC