Heuer, "Calculator, Automatic Chronograph," Ref. 110633. oversized, tonneau-shaped, water-resistant, self- winding stainless steel left-handed wristwatch with round button chronograph, registers, date, bezel with slide rule.
Case: Three-body, polished and brushed, screwed-down case back, winding-crown at 9, chronograph buttons at 2 and 4, hooded lugs, revolving double bezel serving as slide rule to convert weight, volume and distance measurements.
Dial: Navy blue with applied luminous steel baton indexes, outer 1/5th seconds scale, subsidiary dials for the 12-hour and 30-minute registers, aperture for the date. Luminous white baton hands.
Movement: Cal. 12, gilt brass, 17 jewels, straight-line lever escapement, monometallic balance, shock absorber, self-compensating balance spring.
Diameter: 46mm Thickness: 15mm
Introduced in the early 1970's, the large oversize Heuer Chronograph Calculator was to compete with Beitling large oversize Navitimer ref 1806 Chrono-matic which was also fitted with the Heuer-Leonidas inside The Calculator. The watch had limited appeal to the watch buyer but was used by Ferrari Racing Team Engineers and executives on the paddock during the race as a tool watch. It allowed quick calculation of fuel and weight distribution needs at the time when electronic calculators were non existent.
The present watch has gained a beautiful patina, the dial is a darker blue while the hands and subdial have gained a vivid orange. One of the last inexpensive rare 70's Heuer.