IWC Ingenieur 3506.1

IWC. A stainless steel automatic calendar wristwatch, Ingenieur SL, Ref: 3506.1, Circa 1980

IWC. A stainless steel automatic calendar wristwatch, Model: Ingenieur SL, Reference: 3506.1, Date: Circa 1980, Movement: 21-jewel Cal.37531 automatic, No.2424393, Dial: Grey grid, applied gilt hour markers, black outer minute divisions with luminous 5 minute markers, date aperture at 3, gilt pointed baton hands with luminous inserts, centre seconds, Case: brushed and polished tonneau form, screw down back, inner cap, No.2418401, Strap/Bracelet: Black IWC leather, Buckle/Clasp: Signed steel buckle, Signed: Case, dial & movement, Size: 35mm