Providing an unobstructed view of its legendary mechanism, the famous automatic Zenith Chronomaster El Primero “Full Open” is aptly named, since it can now reveal the heart of its performance and precision thanks to a dial that is now entirely open – and openworked.

To ensure a better understanding of the fundamentals governing its flagship Chronomaster collection, Zenith offers its legendary El Primero chronograph in three different versions: with an entirely solid (closed) dial, a half-open (Open) dial, and now an entirely open (Full Open) dial. The latter is the most modern and contemporary interpretation, representing THE major new launch of 2017.

This complete opening enables clients to grasp and visually appreciate the high frequency of the movement, the signature of the legendary El Primero integrated automatic column-wheel chronograph calibre with its 326 components (including 31 jewels), beating at the swift pace of 5 Hz (36,000 VpH) and thus capable of measuring and displaying the time with tenth-of-a-second precision. These attributes are inherited from its illustrious predecessor, the world’s most accurate series-produced chronograph developed by Zenith in 1969. a few subtle nods to the historical version of the El Primero 1969

While the mechanism is now entirely revealed, there are nonetheless a few subtle nods to the historical version of the El Primero 1969: the date window of the 38mm version has been placed between 4 and 5 o’clock just like the original; and the famous blue colour is perfectly identical to the historical version. Combined with the two other colours, anthracite and rhodium, the three galvanic tones make a perfect match serving to magnify the movement.

Three counters complete the picture: the 30-minute counter at 3 o’clock, the 12-hour counter at 6 o’clock, and the small seconds counter at 9 o’clock that notably serves to verify the smooth operation of the movement. A silver-toned inner bezel ring, a black and white minute circle, together with facetted luminescent hands, combine to ensure optimal legibility, without obstructing the view of these captivating inner workings, while the elegant transfer centred inside the sapphire crystal provides the Zenith signature touch.

In terms of the case, the design also reflects the famous historical case of the 1969 El Primero Chronograph. Redesigned and modernised in 2010, this case has become a staple, revisited in every diameter and embodying the quintessence of Zenith’s creativity and timeless classicism. The case-back is of course open with a sapphire crystal revealing a resolutely modern architecture.

Available in two 38mm and 42mm diameters, in steel or a two-tone version with steel topped by an 18K pink gold bezel, and fitted with an alligator leather strap (black for the steel variation and brown for the two-tone steel and pink gold version) or a metal bracelet, this imposing, sturdy and sophisticated chronograph catches the gaze and plunges it into a cutting-edge mechanism by Zenith. Over 50-hour power reserve. Water-resistant to 100 metres.

Specifications:

References:    51.2081.400/78.C810 (42mm, steel and 18K pink gold bezel)

03.2081.400/78.C813 (42mm, steel)

03.2081.400/78.M2040 (42mm, steel with metal bracelet)

51.2151.400/78.C810 (38mm, steel with 18K pink gold bezel)

03.2153.400/78.C813 (38mm, steel)

03.2153.400/78.M2150 (38mm, steel with metal bracelet)

 

Automatic column-wheel El Primero chronograph with date

Entirely open and skeleton-worked dial revealing the legendary movement

 

MOVEMENT

El Primero 400, automatic

Calibre 13½“` (Diameter: 30mm)

Movement thickness: 6.6mm

Components: 326

Jewels: 31

Frequency: 36,000 VpH (5 Hz)

Power reserve: minimum 50 hours

Finishing: Oscillating weight adorned with “Côtes de Genève” motif

 

FUNCTIONS

Central display of the hours and minutes

Small seconds at 9 o’clock

Chronograph:

– central chronograph seconds hand

– 12-hour counter at 6 o’clock

– 30-minute counter at 3 o’clock

Date window at 6 o’clock (42 mm version) and between 4 and 5 o’clock (38 mm version)

 

CASE, DIAL AND HANDS

Diameters: 42mm & 38mm

Thickness: 12.75mm

Crystal: Domed sapphire with anti-reflective treatment on both sides

Case-back: Transparent sapphire crystal

Material: Steel, and 18K pink gold for the bezel of the two-tone version

Water-resistance: 10 ATM, equivalent to 100 metres

Openworked 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

 

STRAPS & BUCKLES

Black or brown clean-cut alligator leather with rubber inner lining

Steel triple folding clasp