ジラールペルゴのインスタグラム(girardperregaux) - 9月8日 15時38分

In order to give the sound its full amplitude, the 48 mm-diameter case with its contemporary design is machined from grade 5 titanium. This metal was chosen because – in this configuration and based on a number of studies conducted in the watchmaking workshops – the algebraic ratio between the size of the (preferably large) case middle and the density (ideally as low as possible) is extremely favourable to acoustic expansion.

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