Zenith El Primero Chronomaster Open Power Reserve

A timepiece that's touted as a technical marvel of pure passion

Each of the watches of Zenith's El Primero Chronomaster Open Power Reserve collection has an opening at 10 o' clock on the dial that allows its wearer to glimpse the beating heart of the famous El Primero chronograph movement, a steady 36,000 vibrations per hour.

The movement vibrates 25 per cent faster than do other movements in the market—while other mechanisms perform 8 vibrations per second, the El Primero caliber does 10 in the same time.The 248-part, 39-jewel movement offers approximately 50 hours of power-reserve.

The movement shows great attention to detail, with a rhodium-plated plate, circular-graining and chamfered bridges, strokes drawn on its hammers, levers and conveyors, and an oscillating weight with 'Cotes de Geneve' guilloche work, and the brand's star logo represented through intricate skeletal work.

The lens of the Zenith Open Chronomaster collection is sapphire crystal with anti-reflection treatment on both sides, while its markers and three hands for the hours, minutes and small seconds are facetted, rhodium-plated and hand-set. The central hand of the chronograph, the hand for the 30-minute counter and for the power reserve all have a blue finish.

The Open model comes in four different versions: a silver or black sun-burst dial in a steel case or silver sun-burst dial in an 18-carat rose gold case or in a rose gold and steel case.

The new collection is in a 42mm case, with a water resistance rating of 100 metres. All the watches come with an elegant brown or black alligator-leather strap.