You can reference the dimensions to something everyone knows too, like an SD card or ipod nano (not something everyone knows, but it's a good way to convert potential ipod nano watch buyers if it's smaller and better looking, which it does seem to be, even compared to the Metalic tiktok variant).
Only the watch body itself is shown: SizeEasy only supports cubic dimensions, so I couldn't find a way to show the wrist band.
Also, SizeEasy requires all three dimensions be provided, and since I couldn't find official dimensions anywhere else I used those cited around the web, for example:
