The first generation Carrera models use a variety of movements sourced from ESA, the predecessor of ETA. Manual-wind movements offered include the Valjoux 72, 92, 7730 and 7731, as well as the Landeron 189.
The second generation models use Heuer’s own Chronomatic movement (a Buren base movement with a Dubois-Depraz chronograph module). Manual-wind variants would follow in the 1970s, but the initial second-generation models are all automatic.

“The first generation Carrera establishes the look that inspires the Carreras of today, while the second-generation model was the first to combine an in-house Chronograph movement and the Carrera case”