Panerai ref 3646 California Dial. Movement Rolex signed manual winding cal 618 Case Oversized cushion shape with screw back case stainless steel signed Rolex, 47 mm. Dial Black lacquered dial known as ” California ” with mixed luminous Arabic and Roman numerals Features According to scholarship, 211 examples are known of the reference, having begun production in 1940. Established in 1860 in Florence, Italy, Officine Panerai was a purveyor of specialized precision instruments like compasses and dive gauges, and by the turn of the twentieth century, the firm manufactured wristwatches. Today, their vintage watches are design icons, easily identified by their oversized cushion-shaped case and clear legible dial. Panerai experimented with various compounds to produce a new luminous material that would be brighter and more effective for their underwater instruments. The luminous powder was named "Radiomir” and patented in France in 1916. Following three years of testing beginning in 1935, they began supplying highly specialized dive watches to the Royal Italian Navy. Evolved from Panerai's prototype model, the reference 2533, their second model was the reference 3646, produced from 1938 to the early 1950s with variants classified from Type A to Type G, each bearing unique aesthetics. Manufactured by Rolex for Panerai, the present lot is fitted with a stunning, black "California-type” dial - a design patented by Rolex in 1941 with half Arabic and half Roman numerals - that retains its gorgeous, original glossy surface. The well-preserved 47mm stainless steel case houses a Rolex-signed movement - the manually-wound caliber 618. Case, movement signed