Like the Patek Philippe Calatrava ref. 6006G featured yesterday, the Zenith Chronomaster El Primero Full Open was another under the radar introduction at Baselworld 2017.

Not in the Zenith press kit or website, the El Primero Full Open is a skeleton dial version of the retro El Primero. And it’s available in both the largish 42mm case, as well as a 38mm size that feels almost like a vintage watch, being the same size as the original El Primero A386 of 1969.

The 42mm

The El Primero Full Open has no dial, exposing all the mechanics usually hidden. This reveals bits of the chronograph mechanism, as well as the open-worked date wheel. While not new – the open dial movement was also used for the El Primero Lightweight – it’s the first time this look is found on a relatively affordable Zenith chronograph.

Detail of 42mm

Notably, the movements inside the 42mm and 38mm versions are slightly different. The larger watch has a slightly larger date wheel to maintain the proportions. Notably, the skeleton date wheel on the 38mm has a more refined look, having thinner numerals.

Note the large date disc on the 42mm

The smaller case size, known as the El Primero Original, is more visually interesting because of the smaller dial, which gives it a more mechanically dense appearance. It is, however, somewhat small by modern standards, and let down by an oversized Zenith logo that’s as large as it is on the 42mm model.

The 38mm

With a smaller date disc that has slimmer numerals

But the 38mm is appealing because it’s an unusual combination: the open dial is reminiscent of modern-ish sports watches from the likes of TAG Heuer, while the case size and style feel like a vintage reissue.

Most of the differences between the two are cosmetic. Both versions are equipped with the El Primero 400, the self-winding chronograph movement that runs at 36,000bph that’s been in production since 1969. Most of the movement has a dark grey galvanic finish with straight graining, giving it a workmanlike appearance.

The 42mm from the back

And the 38mm model

Both the 38mm and 42mm models are available in stainless steel or steel with an 18k pink gold bezel (fitted with matching gilt hour markers and hands). An option of a steel bracelet is also offered. The individual model references are as follows:

38mm, stainless steel – ref. 03.2153.400
38mm, steel with 18k gold bezel – ref. 51.2153.400
42mm, stainless steel – ref. 03.2081.400
42mm, steel with 18k gold bezel – ref. 51.2081.400
Price and availability 

The steel models are priced at SFr9900 or S$15,000, while the version with gold bezels are SFr10,900 or S$16,500. They will be available in stores starting June 2017.

One of Patek Philippe‘s latest releases at Baselworld 2016, but little noticed (the retro perpetual ref. 5320G got most of the attention), is the Calatrava ref. 6006G.

It’s the third generation of an unusual series of watches that are easily one of the most distinctive contemporary Calatrava models, characterised by a functional, vaguely military look blended with elements of Bauhaus.

The series began with the ref. 5000G, produced in 1992 and 1993 in a limited edition of 1000 watches. With a black dial, radial Arabic numerals and a subsidiary seconds between four and five, the ref. 5000G was a departure from the typical Calatrava look and sold well. In the wake of its success variants in other metals with different dial styles were later added.

But the ref. 5000G was typical of the time and only 33mm. So 13 years later in 2005 – product cycles were much longer not that long ago – Patek Philippe returned to the same design with the ref. 6000G. The new model preserved the dial styling, but became more functional with a pointer date, as well as growing the case to 37mm. Again, variations in other colours were subsequently introduced.

A noteworthy example of the model was the one of a kind ref. 6000T in titanium created in 2007 for Geneva charity Children Action, which sold for the third time at auction last year for just over US$240,000.

Unique Ref. 6000T “Children Action” with two-tone dial

Now the quirky aesthetic returns with the ref. 6006G, essentially the same thing but bigger.

The white gold case is now a good 39mm in diameter. Despite being slightly larger the overall proportions have been largely preserved, with the off-centre seconds positioned well and not too far from the edge of the dial, as is often the case is enlarged designs.

Various aesthetic tweaks were also executed, all of which improve the look. The hands are now large, improving legibility, but open-worked so as not to leave them looking too heavy.

The pointer hand for the date is now tipped with an arrowhead, rather than a bracket. Functionally it’s identical but the sharp point looks slightly more purposeful.

Both the minute track and seconds are now finished in white, giving the dial more contrast.

Best of all, however, is an element that’s difficult to discern, at least initially. Though the dial is largely black, it has four different surface finishes, each on a separate level. The most obvious is the concentric stamping on the silvered surface of the minute track and subsidiary seconds.

More notably, the black portions of the dial have three varied finishes, giving the sections different tones despite the colour being the same.

The outermost ring for the date has a grained surface and is slightly raised, while the track for the hour numerals has a circular brushing. And finally the central portion of the dial has a radial brushed finish.

From the back the calibre 240 PS C is visible. The view is no different from other Patek Philippe watches with this calibre, a slim automatic with micro-rotor. Like all Patek Philippe movements it’s equipped with a silicon hairspring.

It’s an attractive and reliable movement, though one could wish for a more artisanal or decorative finish.

Price and availability

Priced at SFr27,000 or S$40,400, and will be available later in 2017, the Calatrava ref. 6006G-001 is priced comparably to other Calatrava models, but the ask is still somewhat steep for a simple watch with a date. But if one is in the market for an entry-level Patek Philippe, the ref. 6006G is arguably the most interesting of the range.