Heuer-Leonidas "Calculator, Automatic Chronograph", Case No. 298504, Ref. 110.633, Cal. 15, 45 x 47 mm, circa 1975

A gentleman's rare, automatic wristwatch with chronograph, 30 min. counter and sliderule function via turnable bezel - for sinistrals
Case: steel, screw back, bezel with tachy scale, crown on the left, original buckle. Dial: blue, applied luminous indexes, auxiliary seconds, 30 min. counter, window for date, luminous baton hands. Movm.: 4/5 plate-micro rotorwind movement, gilt, ground, signed, 17 jewels, finely matted chronograph steel parts, Glucydur balance, incabloc shock protection for balance.