Zenith Chronomaster El Primero Grande Date Full Open

With its powerful build framing a clear view of its legendary mechanism, the new Chronomaster El Primero Grande Date Full Open unveils the heart of performance and precision in the inimitable Zenith style. This self-winding skeleton-worked chronograph, equipped with a column wheel and a silicon escapement, is highlighted by a dial carved in sapphire. This modern architecture with its striking red accents is designed to be admired from both sides.

Framing fascinating glimpses of its sophisticated technical nature, this sturdy stainless steel chronograph catches the gaze in order to draw it into the very heart of a cutting-edge Zenith mechanism. The crystal-clear sapphire dial features two transparent blue- and grey-tinted counters – the aesthetic signature of the original 1969 model – and shows the moon &sun-phases on twin discs at 6 o’clock.

A silver-toned inner bezel ring surrounded by a blue ring, a black and white minute scale, along with luminescent facetted hands and hour-markers, all contribute to ensuring optimal legibility, yet without obscuring the view of the fascinating inner workings. The large date at 2 o’clock – shown by two concentric discs with cut-out numerals – is read off against a bright red background in an engraved aperture, while the slim red-tipped central sweep-seconds hand adorned with the emblematic Zenith star sweeps over this perfectly clear display.

Topped by a domed crystal and fitted with a sapphire crystal case-back, the 45 mm-diameter case – water-resistant to 100 metres – reveals on both sides the outlines of an in-house ‘engine’ with legendary origins. The El Primero integrated automatic column-wheel chronograph beats at the fiery pace of 5 Hz, thereby ensuring and displaying 1/10th second precision. These sterling attributes are inherited from its illustrious predecessor, the world’s most accurate series-made chronograph developed by Zenith and presented in 1969.

Equipped with a silicon lever and escape-wheel, the 332-part El Primero Calibre 4047B  movement drives central hours and minutes hands, along with small seconds, chronograph, large date, moon &sunphase functions, while maintaining an over 50-hour power reserve.

The celestial kinetic ballet is shown on two superimposed discs, with the moon disc rotating every 59 days (two lunar cycles) and the day/night disc making one full turn in 24 hours.

The impressive stature of the Chronomaster El Primero Grande Date Full Open, complete with its fluted crown and double round pushers, is further enhanced by a steel bracelet or a black leather rubber-lined strap. Another version is available with a two-tone exterior (stainless steel case with a pink gold bezel), teamed with a chestnut leather strap.

Technical details
Model: Chronomaster El Primero Grande Date Full Open


El Primero 4047B, Automatic
Calibre 13¼“` (Diameter: 30 mm)
Movement thickness: 9.05 mm
Components: 332
Jewels: 32
Frequency: 36,000 VpH (5 Hz)
Power-reserve min. 50 hours
Finishing: Oscillating weight with “Côtes de Genève” motif

Hours and minutes in the centre
Small seconds at 9 o’clock
– Central chronograph hand
– 30-minute counter at 3 o’clock
Large date indication at 2 o’clock
Moon &Sunphase indication at 6 o’clock

Diameter: 45 mm
Diameter opening: 38.5 mm
Thickness: 15.6 mm
Crystal: Domed sapphire crystal with anti-reflective treatment on both sides
Case-back: Transparent sapphire crystal
Material: Stainless Steel or Bicolor
Water-resistance: 10 ATM

Sapphire dial
Hour-markers: Rhodium-plated or Gold-plated, faceted and coated with Super-LumiNova® SLN C1
Hands: Rhodium-plated or Gold-plated, faceted and coated with Super-LumiNova® SLN C1

Brown calfskin leather strap with protective rubber lining (27.00.2218.813)
Black calfskin leather strap with protective rubber lining (27.00.2218.810)
Metal bracelet (27.02.2530.4047)
Stainless steel triple folding clasp (27.03.0208.940)

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