Two geared hinges straddle the great divide and cling to each side's stabilizer bars with a trio of screws.

The board interconnect cables dip into each hinge housing as they cross over to the other side, preventing them from being pinched as the Duo performs its folding tricks.

It all makes for a refreshingly simple hinge design compared to those we've seen in other foldables. It's sort of like of like a miniature 360° laptop hinge, cable routing and all.

Simple doesn't mean easy. No doubt Microsoft spent loads of time tuning these little folding mechanisms, and their work has paid off. The Duo is incredibly satisfying to open and close.