Patek Phillipe has released numerous complex, high-end timepieces over the years, but some of these devices are a lot more complex and expensive than other. However, probably the most advanced such device is the Star Caliber 2000G, launched back in 2000 after no less than 8 years of development, which, by all accounts, is listed in the top 10 of the world's most expensive watches.

As the name says it, the pocket watch is built around a Star Caliber manual winding mechanism, which is actually formed out of two barrels (movement and chiming mechanism) with bidirectional winding. The device uses a Swiss lever escapement, a screw balance with a Breguet balance spring and provides a power reserve of 24 hours when set to strike in passing (without operation of the minute repeater), barrel limited to 5 revolutions.

However, since we're dealing with a very complex mechanism, it's actually no wonder that it's a bit bulkier than those encountered in the case of other watches, having a diameter of around 55.40 mm, a height of 21.03 mm and a weight of approximately 250 grams.

Now that we've taken a peek at the mechanism that makes this extremely complex watch work, let's see what the actual functions are. Thus, the device delivers a combination of complications for which six patents have been filed, the Star Caliber 2000 being the only pocket watch ever to reproduce exactly the celebrated chimes of the Westminster clock tower in London.

Moreover, its "running" equation of time, synchronized with the perpetual calendar, enables the reading of local mean time and true solar time. The indications of sunrise and sunset, the celestial chart and the moon-phases also accord their movements with the perpetual calendar, whose innovations include a rapid correction feature, which simultaneously adjusts all indications to the perpetual calendar date. A further distinction is the ingenious system for opening the two covers by means of the pendant at three o'clock.

The device is available in several versions from the point of view of the casing, including here 750 yellow, white, or rose gold or in 950 platinum. Additionally, the device's dial is enameled, which further enhances its luxurious design.

The Star Caliber 2000G is yet another one of those ultra-exclusive Patek Philippe products, manufactured in extremely limited editions, and thus available at some astronomical price tags. Only two units are manufactured each year, so it's actually no wonder that one of these things sells for as much 7.5-million dollars, an amount which very few people around the world can afford.