Piaget's obsession with building the world's thinnest watches has resulted in its latest achievement, the Altiplano Ultimate Concept. Measuring just 2mm, the watch is almost as thin as a quarter yet somehow still manages to house a highly complicated movement that is fused with a 41mm case. Using a special cobalt alloy to achieve this engineering feat, the in-house 900P-UC movement, which has a 40-hour power reserve, contains wheels that are .12mm thin and a sapphire crystal that is only .2mm. 

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