Chronomat B31 40 Stainless Steel / Green / Rouleaux

The Breitling Chronomat B31 Automatic 40 AB3114101L1A1 introduces the time-and-date Chronomat format in a 40mm case as part of the 2026 Chronomat redesign. This stainless steel reference has a green dial, a stainless steel case, and a stainless steel Rouleaux bracelet. The case measures 10.99mm thick, giving the B31 Automatic 40 a noticeably different profile from the 42mm B01 chronograph models in the same updated collection. The stainless steel case is water resistant to 200 meters and fitted with a cambered sapphire crystal with anti-reflective treatment on both sides. Its unidirectional ratcheted bezel has raised rider tabs, numerals, and minute indexes, retaining the Chronomat’s functional bezel layout in a three-hand configuration. The 2026 redesign also uses a more integrated case and bracelet architecture, with concealed lugs behind the case. The green dial is arranged around central hours, minutes, and seconds, with a date aperture. Applied hour markers and central hands are treated with Super-LumiNova, while the absence of chronograph counters gives the dial a more open layout than the B01 42 models. The 40mm case size and time-and-date display make this reference distinct from both the larger chronograph models and the smaller 36mm automatic versions. Inside the watch is Caliber B31, Breitling’s COSC-certified manufacture automatic movement introduced in 2025. It runs at 28,800 vibrations per hour and provides an approximate power reserve of 78 hours. This reference is fitted to a stainless steel Rouleaux bracelet with a concealed butterfly clasp and Breitling’s patented micro-adjustment system.