Rolex reference 5500 was in production from 1958 to 1967. Consequently, this is one of the very first iterations of the model. This is confirmed by the fact that the dial bears the Swiss designation, indicating radium luminous numerals. This is a very rare feature, found only on the earliest 5500s: soon after the inception of the model, tritium will be used and the designation will change to T<25. Moreover, this dial configuration – two-tone with lozenge applied numerals, luminous accents, and luminous Alpha hands – is extremely rare.
Additionally, the present piece bears the Super Precision designation, indicating the presence of the calibre 1530. This model could be fitted with two different calibre: cal. 1520, bearing the designation “precision” on the dial, and cal. 1530, like the present “super precision” timepiece. In fact, cal. 1530 will also be used in certified chronometer watches, such as ref. 5504. However, for reasons unknown, no ref. 5500 was ever officially certified.