“Each individual model tried to have logic of their numbering technique but failed miserably,” Mandelbaum continued. “It just represents the full absurdity with the Swiss wanting to think of a numbering program. When the crystals on the 160xx technology of Datejust watches remain made from acrylic, the sloped "pie pan" https://www.watchesworld.com/a-history-of-watch-reference-numbers/