Pre-owned Rolex Explorer II ref 16570 (2004). The Explorer name first appeared in the Rolex portfolio in the 1950s and was initially linked with the famed Rolex Explorer mountaineer’s tool watch. While that model prioritized a simpler, easy-to-read layout, the Explorer II, released in 1971, ramped things up a bit with added functionality and a more robust aesthetic. The newer collection was developed for cave and dark-environment exploration and featured a fixed 24-hour bezel and an additional centrally mounted hand. On modern models like the Rolex 16570 for sale here, the hand is independently adjustable, so it serves both as an AM/PM indicator, as originally designed, and as a second time zone. The ref. 16570 joined the lineup in the late 1980s. It featured many of the same design elements as its predecessor, ref. 16550, but with the newer caliber 3185, and later the caliber 3186. This example from the early 2000s also features newer Super-Luminova, which Rolex has since replaced with Chromalight. Shop Rolex Explorer II Collection