IWC Big Ingenieur Chronograph Automatic Mens Watch IW378401 Unworn. Automatic self-winding movement with 68 hour power reserve. Stainless steel case 45.5 mm in diameter. Exhibition case back. Sapphire crystal. Black guilloche dial with and silver sub-dials. Luminous stainless steel hands and raised index hour Chronograph/Stopwatch complication with minutes and hour totalizers innovative displayed on a single sub-dial. Large central seconds counter for the stopwatch. Small Seconds sub-dial at the 6 o'clock. Date window displayed at the 6 o'clock.Black alligator strap. Fixed stainless steel tachymeter scale bezel.