What is the size when folded of the ORI M9 or Mezzo D9?
This article states the following.

While the D9 doesn't fold quite as small as a Brompton (690x685x360mm to the Brompton's 550x580x280mm)

So the Mezzo D9 folds down to 690 x 685 x 360 mm. Which equates to 27.17 x 26.97 x 14.17 inches.