The watchmaker and innovator Patek Philippe has released a wristwatch that is the first of its kind -  and it's design is so intricate that only 10 will be made each year.

The unique watch is valued at €645,000, but its value is likely to appreciate massively due to its rarity and the prestige of its manufacturer.

The Grande Complication Ref. 5104 PR is the first Patek Philippe watch with a totally transparent dial to reveal the elaborately crafted internal sub-mechanisms within.

These sub-mechanisms include the perpetual calendar, the retrograde date, the minute repeater, the moon-age indication, and, of course, the wheel trains for the hours, minutes and seconds.

The innovative design is intended to reveal the beauty of the watch's inner functions, according to a Patek Philippe statement.

To achieve this was a feat of design innovation and problem solving - and Patek Philip developed a whole new manufacturing process to make the watch a reality.

Innovations in the design include making the sundials transparent and skeletonising the hour and minute hands to avoid obstructing the internal mechanisms.

But the real design genius emerged in ensuring that the watches thin and brittle sapphire-crystal dials function without crumbling to shards - and assure perfect positioning accuracy.

According to Patek Philippe, the watch "takes infinite patience and countless hours of work to create."

With only 10 of these watches being made a year, the Grande Complication Ref. 5104 PR will surely become a holy grail for watch collectors.