The Patek Philippe 5905/1A-001 is a self-winding flyback chronograph with an annual calendar, presented in a stainless steel case with a 42 mm diameter and 14.13 mm thickness. Its olive green sunburst dial features gold applied hour markers, a central chronograph hand, a 60-minute counter at 6 o'clock, and apertures for the day, date, and month. The integrated steel bracelet, inspired by the Aquanaut Reference 5167/1A, showcases contrasting polished and satin finishes. Powered by the Caliber CH 28-520 QA 24H movement, it offers a power reserve of 45 to 55 hours. Water-resistant to 30 meters, this model combines sporty elegance with Patek Philippe's renowned craftsmanship.