Editorial
The G0A43001 holds a record that still has not been beaten: 3.65mm total thickness, achieved by making the movement's mainplate the actual back of the case. Movement and case are the same object. Piaget did not make a thin watch and put a thin movement in it; they redesigned what a watch is.
Piaget has been building ultra-thin movements since the 1950s, and the 9P caliber of 1957 set the template for everything that followed. The Altiplano line formalized that heritage into a named collection in 2004. The G0A43001 arrived in 2016 as the Altiplano Ultimate Concept made production-legal, housing the 1200P caliber in 41mm rose gold.
The 1200P achieves its 2.35mm movement height by eliminating the boundary between case and movement entirely: the mainplate doubles as the caseback, the barrel bridges are integrated into the case middle, and the crown sits flush against the case flank. It is hand-wound, which is the only mechanical solution consistent with that thickness constraint.
At 3.65mm total thickness, the case has essentially no reserve material anywhere. A knock to the crystal or case flank carries nowhere to dissipate, and damage repair on a piece where the movement is the case is extremely consequential. The sapphire crystal is thin by necessity; do not wear this to anything physical.
Water resistance is rated to 20 meters, which is cosmetic rather than protective. Finding an independent watchmaker qualified and willing to service the 1200P is genuinely difficult; Piaget's own service centers are the practical answer, and turnaround times reflect how few technicians work on this caliber. Power reserve is approximately 48 hours, so the watch will stop regularly if it is not your daily wearer, which it probably should not be.
