Zentra Dienstuhr Luftwaffe
Here is a well worn but very reliable Zentra watch with a stamped branch code D for Dienstuhr Luftwaffe.
Typical for these watches the letter D is larger than the six digits. Zentra produced one batch from 600—/605— and this watch is numbered 602778.
Most of the zinc plating has worn off over the years but still looks good. I believe Kriegsmarine watches made by Zentra were chrome plated which was harder wearing.