Notes: In Rolex-speak, “transitional references” refer to those models that include features of preceding versions, in addition to paving the way for future references. Take for example the Explorer II ref. 16550 presented in 1985. With its introduction, the ref. 16550 brought the 40mm case size, a sapphire crystal, Caliber 3085, a longer and thinner arrow-tipped 24-hour hand, and the Mercedes style center hands. Plus, Rolex now offered black or white as dial options on the Explorer II.

Mechanism: Rolex 3085 is a calibre by Rolex. Automatic winding Rolex Caliber 3085 with 27 jewels and adjusted to 5 positions and temperature. This movement provides 24 hour time (second timezone) by means of the red hand which revolves around the dial once every 24 hours. The 12 hour hand can be moved in one hour increments independently of the red 24 hour hand, thereby allowing the wearer to track a second timezone. The local and 24 hour hands are normally left in synchronization with each other to let the wearer know if it is AM or PM (remember this watch was designed for cave explorers who may lose track of day or nighttime). The movement is a C.O.S.C. Certified Chronometer. Self-winding movement, bi-directional winding, 28,800 A/h, 27 jewels, GMT function (dual time zone) and date indication. Used in previous editions of the models GMT-Master II and Explorer II Ref. 16550.

Description: Self-winding movement, bi-directional winding; Chronometer certificate (COSC); Breguet hairspring; Microstella precision adjustment with regulation screws; Kif shock protection.

Family Notes: Rolex introduced the Explorer II in 1971. This watch was not a successor of the Explorer 1016, but an additional timepiece with an additional function. The Explorer II was aimed at speleologists or cave explorers, who could lose sense of time during their work. The Type II came with the additional (24) hour hand, 24 hour scale bezel and a date. The Explorer II (like the I) is a chronometer and the cases were designed to handle 100m water resistance. You only had to open a National Geographic Magazine of the 1970’s and you’d see an Explorer II ad inside.