For enthusiasts of the Explorer line, the Rolex 16570 is a must-have reference. Launched in 1989, the Explorer II was designed for use in low-visibility conditions, making it ideal for scientists, spelunkers, and Arctic explorers. Its AM/PM indicator ensures precise timekeeping, even in the dark. The original Explorer II, the reference 1655, featured a day/night indicator, but the second generation evolved into a GMT watch capable of displaying two time zones. This iteration introduced the choice of a white "Polar" dial alongside the classic black option, further enhancing its appeal. The Rolex Explorer II 16570 is celebrated for its robust 40mm stainless steel case and distinctive 24-hour hand, powered by the reliable Rolex Caliber 3185 movement. This combination of form and function has made it a favorite among collectors and adventurers alike. Production Years: 1989 - 2011 Case Size: 40mm, stainless steel Bezel: Fixed, engraved with a 24-hour scale Dial Options: Black or white "Polar" dial Luminous Material: Tritium, Luminova, or SuperLuminova Crystal: Scratch-resistant sapphire with Cyclops date magnification Functions: Local time (Mercedes hands), reference hour (red 24-hour hand), date window at 3 o'clock Bracelet: Three-link Oyster bracelet Movement: Caliber 3185 or 3186 automatic Water Resistance: 100 meters (330 feet) The 16570, part of a broader lineage of exploration watches, has undergone several changes during its production. Notably, it introduced black surrounds for the hour markers on the white dial, enhancing legibility - a defining characteristic that remains in subsequent models. 1971: Introduction of the AM/PM indicating Explorer II ref. 1655, exclusively with a black dial. 1985: Launch of Explorer II 16550, featuring a GMT function and available in black or white. 1989: Introduction of the Explorer II 16570 with a new movement. 1998: Tritium lume replaced with Luminova. 2000: Luminova replaced with SuperLuminova. 2005: Caliber 3186 replaces Caliber 3185. 2011: Discontinuation of the Explorer II 16570, succeeded by the larger Explorer II 216570. The Explorer II 16570 retains the robust features of its predecessors, including a 40mm stainless steel case, a 24-hour engraved bezel, and a sapphire crystal. Its classic black dial remains timeless, appealing to collectors who appreciate its enduring relevance. The black dial version of the 16570 is celebrated for its versatility, featuring luminous markers for easy reading and a striking appearance. On the other hand, the white "Polar" variation introduces a fresh aesthetic, with black surrounds enhancing visibility. Collectors often favor the Polar model for its uniqueness in the current Rolex sports watch lineup, and it typically commands higher prices on the secondary market. Discontinued in 2011, the replica Rolex Explorer II 16570 is the last 40mm reference, making it a classic choice amidst larger, more exaggerated modern models. Ultimately, whether you prefer the black or white dial, both options offer a timeless blend of style and functionality that makes the Explorer II 16570 a worthy addition to any collection.