IWC, Cal. 83 powered, water-resistant, calatrava design bezel, silver dial, rare 35 mm, screw caseback, circa 1940s. This is a very rare 35mm screw-back waterproof case. The silver dial with arabic indexes, which has aged well, combined with the massive screw back water-resistant case, gives it a wonderful taste reminiscent of military watches. It is equipped with Cal.83, a famous international small-seconds movement. This watch piece is a rare gem with the overwhelming presence that only a 35mm model can give.