On the surface, Panerai has three main case shapes :Radiomir, Luminor, and submersible. However, if we dig a little deeper, we’ll soon find that these variations of the main case style guarantee their own subset. At first glance, for example, the Panerai Luminor looks the same as the Luminor box from 1950. However, these are subtle details, and if we compare a standard Paneri lamp with a 1950 lamp, we can see some differences.
In the first half of the 20th century, Panerai established a working relationship with Regia Marina, the Italian royal navy, to equip combat divers with diving watches. After world war ii, the monarchy was abolished by referendum and Italy became a democratic republic. With the birth of the Italian republic, the reggia pier became a military navy. Panerai continues to supply replica watches to the Italian navy, despite changes in the government and military.
However, Panerai patented “Radiomir” in 1916, and the radioactive paint used to make its watches glow proved to be highly radioactive and dangerous. So in 1949, Panerai applied for a patent for another self-luminous substance, this time based on a safer form of tritium, and called it “luminescence. ” 
In addition to lume, which is constantly being refined for use on the dial, Panerai also shows a constantly evolving case design. In 1950, Panerai made its debut in the previous decade with a huge 47mm cushion-shaped box with heavy earpieces, and now has a protective bridge attached to the curved crown. This large crown protector is operated by a small lever that pushes the crown securely into the watch case to create a watertight seal when locked, and releases the crown when windings and Settings are unlocked.
By the early 1990s, Italy had cut military spending, threatening Panerai’s business because it relied on naval demand for its revenues. Panerai was forced to turn to the civilian market for replica breitling watches. In 1993, Panerai introduced three watches, including the Luminor. The virgin glow is a modern interpretation of the old Panerai watch from the 1950s, with a half-moon crown protection highlighted on the right side of the 44mm cushion-shaped case. Panerai Luminor soon became the brand’s flagship watch.
In 2002 (when Panerai was already part of Richemont), Panerai released a limited edition watch in the form of Luminor PAM 127. A faithful replica of the 1950s Panerai 6152/1, the watch includes a 47mm cushion-shaped case, a high-domed crystal covering the dial, and, of course, crown protection. Panerai also added the word “1950” to the black time scale to remind people of the original year of the watch. The success of PAM 127 — now affectionately known as “Fiddy” — set the stage for the next Luminor 1950 series.
