CHPTR_Δ 40mm KAIROS (Chapter Delta) is a more compact expression of BA111OD’s first manufacture watch complication, a unique timepiece that represents time in a revolutionary way.

Developed with renowned watchmaker Olivier Mory, it introduces an entirely new approach to time display. Instead of simply rotating a hand around a central axis, the movement was conceived to roll a satellite hour wheel around a fixed central hour wheel. This creates a deltoid trajectory, meaning the tip of the hour hand traces a triangle, a world premiere in watchmaking. With its asymmetrical reading of time, CHPTR_Δ challenges convention while offering a more compact and versatile presence on the wrist.

This grey execution brings a vibrant and contemporary dimension to the concept, highlighting its architectural design and distinctive mechanical expression in a refined 40mm format.