A stainless steel/18K yellow gold Rolex
Chronograph Daytona, 116523. It has an integral stainless steel and 18k yellow gold Oyster bracelet, a scratch resistant sapphire crystal, and round chronograph push buttons.
The screwed-down Triplock winding crown is protected by the crown guard, and the 40mm diameter solid three-body case, screwed down solid case back, Oyster bracelet and crowns are polished/brushed.
The dial is steel gray with luminescent baton hands, faceted luminescent "boat-shaped" baton hour index markers, a central sweep chronograph hand, and an outer minute track.
There is a tachometer graduation on the gold bezel to 400 units per hour. It has a subsidiary dial for the small seconds at the 6 o'clock position, a 12-hour subdial at 9 o'clock, and a 30-minute register at 3 o'clock.
It's water resistant to 100 meters/330 feet, and the 12mm thick case, and dial.