Zenith Defy El Primero

Ref. 95.9000.9004/78.R582

The El Primero name has belonged to Zenith since 1969, when they produced one of the first automatic chronograph movements. The calibre 9004 is what that lineage eventually built toward: a double-escapement architecture in which two independent gear trains run simultaneously, one governing the time at 5 Hz, a second beating at 50 Hz to drive the chronograph alone. That second frequency is what makes 1/100th-of-a-second measurement possible in a mechanical watch — the large central chronograph hand completes a full rotation every ten seconds, so a single step is a hundredth. The skeletonised dial is functional here rather than decorative. With the movement exposed through the casework, you can watch both escapements at work side by side, which is a different experience from looking at a conventional skeleton. At 44mm in titanium the watch sits large on the wrist but carries far less mass than steel at that diameter, and the alligator-over-rubber strap — built for sport use — keeps the case stable during the kind of timing for which the movement was designed. The linear power reserve indicator at twelve tells you at a glance how much is left in the chronograph module specifically, which matters because the two mechanisms wind independently.

Reference

95.9000.9004/78.R582

Brand

Zenith

Case size

44mm

Case thickness

14.50mm

Lug width

23mm

Case material

Titanium

Case shape

Round

Dial

Black

Crystal

Sapphire

Movement

Automatic

Calibre

9004

Functions

Chronograph, Power reserve indicator, Skeleton dial

Water resistance

100m

Bracelet / strap

Leather strap

Strap colour

Black

Clasp

Deployant clasp

Lume

Super-LumiNova

Retailer

Goldsmiths