CASE: Three-body, solid, polished and brushed, screwed-down case back, crown and buttons, winding crown protected by the crown guard, tachometer graduation on the bezel to 400 units per hour, sapphire crystal.DIAL: Mother of pearl with applied white gold Arabic numerals and luminous white gold baton indexes, subsidiary silver ring dials for the seconds, the 12-hour and 30-minute registers, outer 1/5th seconds scale. Luminous white gold baton hands.MOVEMENT: Cal. 4030, rhodium-plated, oeil-de-perdrix decoration, 31 jewels, straight-line lever escapement, monometallic balance adjusted to 6 positions, shock absorber, self-compensating free-sprung Breguet balance spring, Microstella regulating screws.Dial, case and movement signed, in good conditionDIAM: 40 mm THICKNESS: 13 mm