The Zenith Chronomaster El Primero Full Open, launched in 2017, is a direct reflection of Jean-Claude Biver’s influence on the brand that he currently directs. He specifically wanted to open up the dial completely. The Chronomaster was previously available with an entirely solid dial, and a version with a half-open dial revealing just the balance and the silicon escape wheel and lever. The Full Open version looks a bit like a Hublot (another Biver brand) with its entirely skeletonized dial.
The watch is available in several versions and in two sizes, 38 mm and 42 mm, all 12.75 mm thick. The 42 mm version has the date at 6 o’clock, the 38 mm version shows the date at 4.30, purely by placing a surface with a touch of red behind the date wheel at this point. Though it’s an open dial watch, you can’t really see much from the front: mainly the skeletonized date wheel. The chronograph counters and the small seconds dial at 9 o’clock all overlap, but they are all perfectly legible, and this is an improvement over the original Chronomaster design. Apparently the brand reacted to response from bloggers who commented on this. Personally I would have preferred a complete seconds scale, not interrupted by the numerals. The hour appliques are very nice, floating above the movement, a fine combination with the hour and minute hands. The Zenith logo and name are on the inside of the sapphire watchglass.
The case is a modernized version of the 1969 El Primero Chronograph. It has an open caseback revealing the movement. The steel versions have a black alligator strap or metal bracelet, the two-tone steel and pink gold versions have a brown alligator strap or a metal bracelet. Water resistance is 100 metres.
The El Primero 400 is an integrated automatic column-wheel chronograph, with 326 components including 31 jewels. It runs at 5 Hertz, 36,000 vibrations per hour, and so has a precision of a tenth of a second for chronograph readings. Power reserve is over 50 hours.
References and prices
The Zenith Chronomaster El Primero Full Open is more expensive than the basic Chronomaster El Primero with complete dial, which starts at €6,900 for the steel version. The Full Open starts at €9,600. Here are the references:
03.2081.400/78.C813 (42mm, steel, leather strap) €9,600. $9,600, £9,020
51.2081.400/78.C810 (42mm, steel with pink gold bezel, leather strap) €11,200, $11,200
03.2081.400/78.M2040 (42mm, steel with metal bracelet)
03.2153.400/78.C813 (38mm, steel, leather strap) €9,600. $9,600, £9,020
51.2151.400/78.C810 (38mm, steel with pink gold bezel, leather strap) €10,600
03.2153.400/78.M2150 (38mm, steel with metal bracelet)
Read more at the Zenith website.