This is a large and very fine 36.5mm. stainless steel IWC INGENIEUR ref. 666 in stainless steel dating to the 1950’s and housing the caliber 853 automatic winding movement. The inner soft iron case protects the watch from magnetic fields (as it was designed to do so). The large steel case with screw back displays extra fine condition. The original ivory dial with original gold toned Dauphine hands and arrow markers looks fabulous. This is a very fine example of a rather uncommon vintage IWC tool watch.