The 5951P-001 is one of the most complicated, integrated chronographs made by Patek Philippe that was first introduced at BaselWorld in 2011. This model was in production until 2014 and has become one of the most sought-after pieces from Patek Philippe. The 5951P-001 has a cushion-shaped platinum case that is 37mm in diameter with an exhibition case back, a screw-down crown and a rounded fixed bezel. The dial is black with platinum index hour markers, three sub-dials, three-date windows, a moon phase dial, and feuille platinum hands. The 5951P-001 CHR 27-525 PS caliber is one of the most complicated and intricate calibers in the industry. The caliber is manually wound and has a perpetual calendar, day/night indication, moon phase functionality, a split-seconds chronograph and a power reserve of 48 hours. The case is paired with a black alligator leather bracelet with intricate red stitching to tie in with the dial design and has a platinum pin buckle. It has a water resistance of 30 meters (98 feet).