The 184.108.40.206.01.002 is the mid-size cal. 2500 Omega Seamaster with black dial and ceramic bezel insert.
The OMEGA 300 was the perfect accessory for professional divers. No one was in a better position to describe the OMEGA Automatic Seamaster 300 at work then Alain Julien, a French commercial diver who wore his “300” on a daily basis in 1958 and 1959. Julien wrote “The Seamasters are of extraordinary solidarity and precision. No other watch competing with Omega has ever resisted the hardships linked to such underwater work as seabed prospecting, pipe laying, repair of works such as piers and dams, and recovery work on wrecks. The Seamaster 300s presented no defects. Despite the shocks of often extreme brutality, the cold water, and the great depths at which we work, they remained of an astonishing robustness and precision. By way of indication, each of us has dived more than 1,500 times."