Type XXI 3817STX23ZU
Type XXI flyback chronograph in steel with elapsed minute register on a centre hand. Self-winding movement with date and subdial for the seconds. Balance spring in silicon. Day/night indicator and 12-hour totaliser. Graduated rotating bezel. Luminescent hands and hour-markers. Screw-locked crown. Sapphire caseback. Water resistant to 10 bar (100m). Diameter: 42mm.