CHPTR_Δ is the first BA111OD manufacture watch complication: a unique timepiece that represents time in a revolutionary way.

The CHPTR_Δ.6 [PHANTOM] is distinguished by its sophisticated anthracite hue. The meticulously crafted details give this piece a touch of discreet luxury within timeless elegance. Rather than simply rotating a hand around a central axis, the movement was designed to "roll" a satellite hour wheel around a fixed central hour wheel. When a wheel is rotated around another wheel, the trajectory described by any point on this satellite wheel is a cycloid. There are several types of cycloids: in this BA111OD chapter, the chosen cycloid is a deltoid (with a ratio of 1/3), and as a result, the trajectory described by the tip of the hour hand is... a triangle.

Created with the help of renowned watchmaker Olivier Mory, CHPTR_Δ's asymmetrical reading of time is a world premiere that promises to captivate and inspire anyone who seeks a new and unique way of reading time.