Officine Panerai Brevettato "Radiomir" / Rolex SA, Genève Suisse, 31 Victoires, Haute Precision, Brevetee, Case No. 260663, Type D, Ref. 3646, Cal. 618 / Type 1, 47 x 52 mm, circa 1944

An important military divers watch of the German Navy - only 60 watches of this kind are known today
Case: steel, screw back. Dial: black, luminous Arabic numerals/indexes, luminous hands. Movm.: bridge movement, nickel-plated, "fausses côtes" decoration, chatoned, 17 jewels, monometallic screw balance.

Extensively discussed and illustrated by Ralf Ehlers & Volker Wiegmann, http://www.vintagepanerai.com, the highly recommended website for vintage Panerai watches.