Heuer, Switzerland for Beechcraft, United States. 3500 Calculator automatic chronograph watch, ca. 1970s. Stainless steel case and bracelet. Dark blue dial with two subsidiary dials and a date window. The watch is powered by a caliber 12, 17 jewel automatic movement. Case; Diameter: 47 mm. Band; Width: 20 mm. Lug; width: 9 mm. Gross weight: 136 g.