This reverse mounted case example is the product of a colaboration between Comex and Jacques Cousteau which took about 4 years to be first seen in 1970. It was what was perhaps the first waterproof watch designed and built specifically for the diving professional. PloProf translates from french as Plongeur Professionnel or Professional Diver.  Fully functional, the watch is in honest condition.
 
*** The pictures may show the reflection of the camera lens, black spots mostly ***

Details:
 
Make: Omega 
Model: Seamaster 600 Ploprof
Reference:  166.077
Year: 1972
Material: Stainless
Dimensions: 45mm
Crystal: Mineral Glass
Movement: Automatic
Bracelet/Strap: Leather
Box/Papers: No/No