a variety of chronographs that Heuer introduced in the 1970s
Reference 13-1 Chronograph
Reference 13-1 has a black-coated case, with two working registers and a date, powered by the Valjoux 7765 movement
Reference 741-1 Chronograph
Reference 741-1 has a chrome-plated case; dials has two registers and a date, with tachymeter scale; powered by the Valjoux 7734 movement
Reference 2000 Chronograph
Reference 2000 has a stainless steel case; dial marked "Chronographe Incabloc 17 Jewels", with two registers and no date, powered by the Valjoux 7733 movement.
Reference 905 Chronograph
Reference 905 has a stainless steel case; dial marked “Chronographe Incabloc 17”, with two registers and date; Tachymeter and Telemeter scales; powered by the Valjoux 7734 movement.