On Baselworld 2017, Zenith released the Chronomaster El Primero Grande Date Full Open watch. Featuring a dial carved in sapphire, a dual-disc sun and moon phase, and for the first time in the Grande Date and a fully skeletonized architecture. What a design!

Inside beats a 5Hz, high-frequency, in-house El Primero Calibre 4047B. The self-winding chronograph movement operates at 36,000vph and has a 50-hour power reserve. Because it beats at 5Hz, this allows for an accurate display down to a tenth of a second.

The dial shares the same layout as the previous versions, but for the Zenith Chronomaster El Primero Grande Date Full Open, the architecture is on full display. The transparent date window remains between 1 and 2 o’clock with a red backdrop, and the moon-phase (complete with a 59-day double-lunar cycle) at the 6 o’clock position adds a splash of additional color to the traditional red, blue, and grey Zenith palette. 

This great Zenith is in near mint condition and just came back from a full service at Zenith! Comes as a full set with factory warranty until 10-2024!