As described in a video by our friend Tim Mosso: a rectangle in a rectangle in a rectangle :) I love that aspect too. Much more than Reverso with round sub-dials. Best, E.
The watch in my collection I've owned longest is a Reverso Duo with, frustratingly, a round subdial. I wasn't keen enough in my watch vision back in 2011 to see what a shortcoming that was, but by now it's got too venerable a place in the collection to gi...