Breitling Montbrillant Datora ref. A21330: 43 mm steel case with slide‑rule and beaded bezel. Movement: Breitling Caliber 21 (Valjoux 7751 base) full calendar chronograph with day/date/month and moonphase, COSC. Sapphire crystal; ~30 m WR. Dials in black, silver/ivory.