It is the watch of choice among architects and writers, a multiple prizewinner, and the iconic NOMOS timepiece: Tangente. With clear lines and perfect proportions, tempered blue hands on a white silver-plated dial, a strap from Horween Genuine Shell Cordovan. And of course—the hand-wound NOMOS DUW 4001 caliber, visible through the sapphire crystal glass back; a classic itself. Ref. 139 Case stainless steel sapphire crystal glass back Glass sapphire crystal glass Winding manual Dimensions diameter 35.0 mm height 6.6 mm lug-to-lug 45.0 mm Water resistance 5 atm (splash-proof) Dial galvanized, white silver-plated Hands steel, tempered blue Strap Horween Genuine Shell Cordovan black lug width 18 mm