Some tachymeter/telemeter/pulsometer watches showcased spiral-model “snailed” scales on the dial. To the Chronoscope, Omega opted for a more symmetrical seem that encompasses a several concentric circles that come with the critical scale data even though also not materially distracting from core dial legibility. The ref. 16800 tends to get missed https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/