The Rolex Explorer II Reference 16570 featuring a Z-Series serial number (circa 2006–2007), a Caliber 3185 movement, a "no-holes" case, and a black dial is a highly desirable transitional watch that represents the intersection of neo-vintage charm and modern robustness.

• The Movement (Caliber 3185): While the Z-series marked the beginning of Rolex's transition to the Caliber 3186, many Z-serial units still house the legendary Rolex Caliber 3185. It features a "flyer" independent jumping hour hand to track a second time zone but is known for a slight, harmless "wobble" of the GMT hand when adjusting time.

• NoLugHoles Case & SEL: The case is a "no-holes" (or hole-free) design, which Rolex phased in fully around 2003–2004. It comes paired with Solid End Links (SEL) on the Oyster bracelet, providing a more solid, modern luxury feel compared to older stamped-steel end links. 

• Black Dial & Luminova: The black dial variant presents a sleek, glossy aesthetic with white gold surrounds on the hour markers. Models from 2007 utilize crisp Super-LumiNova for nighttime legibility instead of the aging tritium found on 1990s variants. 

• No Engraved Rehaut: Unlike the very late M-series and G-series 16570s that featured the repeating "ROLEX ROLEX" engraving on the inner bezel ring, a Z-series with a 3185 movement almost universally features a clean, un-engraved rehaut.