The movements used in both the Doxa SUB 300T and 600T are the 25 Jewel ETA 2824-2, which is a modern version of the original SUB 300T's 17 Jewel ETA 2852 movement. It is rated as 42 hours power reserve, 28800 bph with an Incabloc anti-shock system and has been produced since 1972. This movement is the workhorse in a number of watches at all price levels and has a reputation for reliability and robustness. The rotor is mounted on ball bearings, the balance is either nickel plating or Glucydur, and the balance spring is flat in Nivarox 1 or 2. Its popularity virtually ensures that parts should be available for a long time to come and any watchmaker should be able to service or adjust it without a problem.

25 Jewel ETA 2824-2 automatic with date function Swiss Made Diameter 25,60 mm, Height 4,60 mm Mechanical lever movement, manual winding or bi-directional self-winding mechanism with ball bearing Display by means of hands : hours, minutes, seconds Instantaneous date, date corrector 28,800 vibrations per hour (4 Hz) Regulator system ETACHRON with fine-timing device Winding stem with 3 positions Hack second hand ability Movement modified and decorated by DOXA