Caliber P.9003 boasts a power reserve of three days, stored in two series-connected spring barrels, and a very efficient automatic winding system with a bi-directional winding rotor. In terms of regulation, the hour hand, which is connected to the date, can be moved independently and in jumps of one hour, without interfering with the minutes and seconds hands. When setting the time, a mechanism stops the balance and zeroes the seconds hand so that the time can be synchronized precisely with a reference signal.
The black dial — assembled in Panerai’s classic “sandwich” design, with a luminous layer between two disks — has Arabic numerals at 12 o’clock and 6 o’clock and, on the outermost edge, the numerals and indices for reading the second time zone, which are indicated by the arrow-tipped central GMT hand. The date window is at 3 o’clock and the small seconds counter at 9 o’clock.
Like other Panerai Luminor watches, the PAM00531 has the trademarked crown-protection device with a locking lever, here made of brushed steel to contrast with the polished steel of the case. The classic Panerai Luminor 1950 case measures 44 mm in diameter and made of AISI 316L stainless steel, which has a low carbon content and is highly resistant to corrosion. The Panerai Luminor 1950 3 Days GMT 24H is water-resistant to 300 meters, and is fitted with a black leather strap with ecru stitching. The watch, which retails for $10,100, is also supplied with a spare rubber strap, a steel screwdriver and a tool for replacing the strap using the push-pieces in the lugs.