This is a stainless steel IWC Pilot Chronograph (Flieger chronograph), reference IW370603. It has an alligator leather strap with a stainless steel IWC tang buckle, and a domed scratch resistant sapphire crystal that's secured against displacement by extreme drops in air pressure. There is a screw-down solid engraved stainless steel case back with "Der Fliegerchronograph – IWC." It has a stainless steel screw-down winding crown and round pump chronograph pushbuttons. There is an antimagnetic inner soft iron case. The 39mm diameter solid two-body case, downturned lugs, and stepped bezel are brushed/polished. The dial is black with tritium baton hands, quarter-hour baton indices, and luminescent dot and Arabic numeral hour markers. There is a minute/one-fifth second track around the perimeter, and a white luminous center sweep chronograph hand. There are side-by-side aperture windows for the day and date at the 3 o'clock position. There are three subsidiary dials including a 30 Minute register at 12 o'clock, a 12-Hour indicator at 6, and a small constant seconds at 9:00 o'clock. It's water resistant to 60 meters/200 feet, and the 15mm thick case, dial, and movement are all signed.
The mechanical automatic self-winding IWC caliber 7902 movement is a modification of a base Valjoux 7750 engine. It's rhodium plated, with oeil-de-perdrix embellishment. It's constructed with 25 jewels, a shock absorber mechanism, and a straight-line lever escapement. It includes a monometallic balance that's adjusted for heat, cold, isochronism, and five positions. There is a self-compensating flat-balance spring, a micrometer regulator, and a hacking seconds device for precision time setting. The mechanism oscillates at a frequency of 28,800 vph (4 Hz).