Caliber B04

About the Breitling Caliber B04

The base is the in-house B01, a column-wheel chronograph with a vertical clutch, a 70-hour reserve, 28,800 vph and 47 jewels, certified by the COSC. The module lets the wearer jump the local hour hand forward or back in one-hour steps from the crown while the chronograph runs, with the date following, so a time-zone change is a few clicks rather than a reset. The red 24-hour hand reads home time against the dial's inner scale.

The library finds it under 56 Chronomat B01 44 references, the 44 mm Chronomat 44 GMT and the 47 mm Chronomat GMT, 11 Navitimer GMTs, 11 Super AVI B04 Chronograph GMT 46s, and one each in the Transocean, Chronoliner and Bentley lines. Cases run from 43 mm to 49 mm, with 44 mm at 38 references, 47 mm at 18, 46 mm at 12 and 48 mm at 11.

The Caliber 24 is the older 7754-based chronograph GMT, and the Caliber 32 the three-hand GMT without a chronograph.