The Patek Philippe Calatrava Perpetual Calendar Ref. 5139G is a masterpiece of horological engineering, featuring a 38mm 18k gold case that exudes luxury and sophistication. The black dial provides a striking backdrop for the perpetual calendar complications, which include date, day, and month indicator. Powered by an automatic movement, this watch boasts a remarkable 48-hour power reserve, ensuring reliable timekeeping even when not worn. A premium leather strap complements the gold case, while the watch also comes with a two-year rewind warranty, providing added peace of mind for the owner.