Today, we bring you our hands-on review of the exceptional Patek Philippe Annual Calendar Chronograph ref. 5960/1A. When the ref. 5960P was first launched in 2006, this reference won instant acclaim. It was the manufacture's first self-winding chronograph, manifested a new and unique style with its prominent monocounter and three large calendar apertures, and quickly established itself as one of the most coveted timepieces of the Patek Philippe portfolio. The success story continued with further versions in rose gold. Now, the letter 'A' in the model designation 5960/1A —which stands for 'acier', steel in French—, announces a paradigm change. The Annual Calendar Chronograph in stainless steel is not only the latest sibling of its lineage but had also replaced the gold and platinum versions.

Patek Philippe's stainless steel watches have always ranked among the most desirable timepieces because they were crafted only in small numbers. They were not regularly produced until 1976, when the manufacture introduced the casually elegant Nautilus line. Its memorable slogan: "One of the world's most expensive watches is made of steel." Twenty years later, the attractively stylish Aquanaut was also endowed with a stainless steel case. With very few exceptions, such as the ultra-thin ref. 5950A split-seconds chronograph which has been in the collection since 2010, all other Patek Philippe men's watches were systematically cased in gold or platinum. As regards this strict distinction between casual and classic watches, the new ref. 5960/1A is another one of these seductive exceptions.

The Patek Philippe Annual Calendar Chronograph ref. 5960/1A is fitted with a highly polished stainless steel case measuring 40.5 mm in diameter, a display case back and is water resistant to a depth of 30 meters. Equipped with pump chrono pushers, the watch stays true to Patek's design principles when it comes to chronographs. To ease the operation of setting the annual calendar, the watch is fitted with three correctors on the case band.

Fitted with a stunning silvery opaline dial with blackened gold applied hour markers and red chrono seconds and minute hands, the ref. 5960/1A is not only elegant but very sporty at the same time. The dial layout is very well balanced featuring a monocounter 12-hour chronograph at 6, day-date-month apertures between 10 and 2, a power reserve indicator at 12 o'clock and a black and white minute rail track fitted with luminescent markers. As you can appreciate in the pictures, the different layers around the dial make it pop even more. In a few words, this is a dial that you can stare at for hours. If you look closely at the monocounter for the 12-hour chronograph, you'll notice the big differences between its design and the design of the monocounter on its platinum and gold predecessors reviewed here. For those of you wondering what the small aperture inside the monocounter is, it is a clever night/day indicator. As expected from an Annual Calendar the movement automatically recognizes months with 30 and 31 days and, assuming that the watch is always running, only needs to be manually corrected on March 1.

Powered by the Patek Philippe automatic calibre H 28-520 IRM QA 24H with flyback chronograph and annual calendar, this watch comes with a power reserve of 55 hours when fully wound and the movement is fully visible via the display case back. The movement is composed of 456 parts, 14 bridges and 40 jewels. This is a movement that beats at a frequency of 28,800 vph and equipped with a Gyromax balance and a 21K gold rotor. The chronograph calibre is based on the venerable column-wheel principle for controlling the start/stop commands. However, it differs from classic Patek Philippe column-wheel chronographs by virtue of a remarkable innovation: the clamps do not control the engagement of a lever mounted clutch wheel with the chronograph train but instead act on a disk clutch that transmits —chronograph running— or interrupts —chronograph stopped— the power between the fourth wheel and the chronograph hand. This is a highly reliable solution that makes it possible to use the chronograph hand as a continuously running seconds hand without affecting the rate accuracy of the watch.

Now, let's talk about Its integrated stainless steel bracelet. Right after its unveiling at Baselworld 2014, some collectors loved it and others hated it. Ourselves, we were not very in love with it but didn't hate it either. Even though we had already perused the watch during the press presentation at Baselworld 2014, it wasn't until now that we were able to really examine the bracelet with the utmost attention to detail and while working on this hands-on review, all we can say is that its design flows quite nicely with the overall look of the watch and its 'rice bead' links are a pure work of art. If you look closely at the pictures below, you will see what we mean —each bead link has a small concave area at the bottom of it. The bracelet is very comfortable with a nice weight to it and is fitted with a double folding clasp with small fold over clasp signed with the Calatrava cross.

On the wrist, this watch exudes pure elegance but its red and black accents make it look very young and contemporary. The watch wears true to its size and with unparalleled wrist presence. This is a watch perfectly made for any type of setting or to go well with any outfit —even with short sleeves it looks just stunning. Whether you are a young or an older Patekaholic, this is a very special watch that will make history once we look back at the brand's history in 20 years.

Sticker Price $54,800 USD. For more info on Patek click here.