• Brand: OMEGA
  • Year: 1936
  • Model: Chronograph
  • Reference: CK710 AF
  • Calibre: 33.3
  • Movement: Manual
  • Material: Stainless steel
  • Features/complications: Chronograph complication 
  • Dial: Enamel dial with a Base 1000 track, seconds and chronograph minute sub-dials. Flame blued hands and Breguet numerals.
  • Case dimensions: 32mm
  • Bracelet/strap: Leather strap
  • Accessories: Extract from the archives
  • SKU: 03077


Developed by Lemania in 1933, the OMEGA manual winding chronograph 33.3 and was a technical marvel for its time and is still revered by collectors today. The 33.3 was far larger than most chronographs for its time and became a favourite of many military forces as well as explorers of the day. The three-piece stainless-steel case is in great condition with well-defined crisp edges to the lugs.

This calibre was initially produced with an independent start-stop reset mono-pusher located at 2 o’clock. However, like the calibre 28.9, a version with two pushers was introduced in 1938: a separate stop-start pusher and a reset pusher integrated into the crown or at 4 o’clock. Anti-shock and anti-magnetic was introduced in 1942 and the name of the calibre 33.3 CHRO changed in 1949 as two lines of chronograph models were introduced: the calibre 170 used to equip non-resistant models and the calibre 171 to equip water-resistant models.

The calibre 33.3 CHRO was regarded as a very precise and reliable movement with 14,000 pieces produced until 1952.