CASE: Three-body, polished, bi-directional revolving reeded and graduated bezel, faceted lugs, transparent screw-down case back, sapphire Crystals.DIAL : Midnight blue with painted luminous Arabic numerals and baton indexes in 24 hours, subsidiary guilloché silvered dials for the seconds, the 12-hour and 30-minute registers, outer graduation for the slide rule and the telemeter. Luminous steel baton hands.MOVEMENT: Cal. 24, rhodium-plated, 17 jewels, straight-line lever escapement, monometallic balance, shockabsorber, flat balance spring, micrometer index regulator. Dial, case and movement signed, in very good conditionDiam. 41 mm. Thickness: 13.5 mm.NOTE: It is thought that less than 3000 examples of this series were made.