It is the Speedmaster Day Date as oposed to Speedmaster Professional.
The Day Date was equipped with a 7750 based Cal 1164 movement whereas the Pro has a manual wind Lemania based Cal 1861 movement.
The Day Date uses a saphire crystal, Pro uses acrylic (Hesalite) crystal.
Pro has a 3,6,9 subdial layout.
http://www.omegawatches.com/collection/ ... h/32105000Some will argue that the Day Date is not as classic as the Pro. A debate that will never be resolved I guess.
One of these discussions here:
http://forums.watchuseek.com/f20/omega- ... 71943.html