This clock uses some small colored transparent windows to cancel out certain colors and show others through in order to display the time. Because of this the Seeing Double Clock is then able to display the minutes and hours in the same spot, which are only shown by the appropriate hand passing over them.
It’s kind of works the same as the old-style 3D glasses, except instead of you wearing them the hands of the clock do. If you’ve never learned to read a dial clock but want to make it look like you kinda’ can, then this is your answer. The Seeing Double Clock measures 16-inches in diameter and goes for about $50.