Chronomaster El Primero Grande Date Full Open


In 1969, Zenith introduced the first fully integrated column wheel automatic chronograph movement El Primero with an accuracy of 1/10 seconds. This high-frequency design was applied to Chronomaster El Primero Grande Date Full watches. In the Open watch, the high-performance and ultra-precision core is displayed in an unparalleled Zenith style. Let’s take a look at this clearly visible mechanical watch-Zenith El Primero Chronomaster Grande Date Full Open Automatic Watch 03.2530.4047/78.C813.

Modern Modernist Architectural Style

The Zenith Chronomaster El Primero Grande Date Full Open self-winding chronograph watch is  assembled column wheel and silicon escapement wheel, the carved sapphire dial adds charm, showing the exquisite design style of fashionable men. Decorating with striking red accents, you can enjoy the charm on both the upper and lower sides.


The 45mm diameter case is made of strong and sturdy steel, and it is topped with curved crystal glass and sapphire crystal case back which is processed double anti-glare treatment, and you can see the legendary independent “engine” on both sides. The El Primero star-speed integrated automatic column wheel chronograph movement vibrates at a high frequency of 5 Hz for precise timing.



The clear and bright skeleton dial is distinctively designed with two blue and grey chronograph sub-dials at 3 and 9 o’clock. It continues the 1969 classic design and features two solar and moon phases at 6 o’clock. The silver inner bezel design is matched with the blue circle, which is exquisite and conspicuous. The black and white design is very clear at the moment, which is easy for the wearer to read clearly, but does not interfere with people’s wonderful operation inside the watch. There is a big calendar at 2 o’clock, and two hollow digital concentric discs are displayed. Below the 12 o’clock position, there is a star logo at Zenith, which is full of personality.

The moon phase display rotates once every 59 days (two months of operation), and the day/night display rotates one full circle every 24 hours—two dials overlap, which reproduces the dial of the celestial body like a beautiful ballet.


The side of the watch has a crown with a groove design, which is convenient for the wearer to accurately calibrate. There are two-way rotary buttons between the top and bottom of the crown, so the timing operation is flexible and quick.


The strap is made of black calfskin, very ideal for noble gentleman, with rubber protective lining, it perfectly enhances wearing comfort and reduces wear. This watch is also available in a stainless steel bracelet.


The transparent design of the sapphire crystal at the bottom of the watch allows the wearer to observe the operation of the movement. The interior is equipped with a high-frequency El Primero 4047B movement, and the hollow surface shows the heart of the El Primero star-speed movement. Consisting of 332 components with a silicon pallet and escape wheel, the vibration frequency is up to 36,000 times per hour (5 Hz), the power reserve is about 50 hours, and the oscillating weight is decorated with a “Geneva ripple” pattern. Water resistant is up to 100 meters.

Since 1865, Zenith has been shouldering the mission of high-end watchmakers, creating a piece of fine craftsmanship with superb watchmaking craftsmanship and adhering to the fine craftsmanship of the ancestors to create the future and stay ahead of the trend of development. The subsequent launch of the Defy El Primero 21 is to increase the precision of the mechanical movement to a higher precision field, and to surpass itself.