Rolex Explorer II: Every Reference from 1971 to Today

The Rolex Explorer 2 is one of those watches that rewards research. A tool watch built around a fixed 24-hour bezel and a dedicated GMT hand, it was born in 1971 specifically for cave explorers who needed to distinguish day from night in total darkness. Over five decades and five distinct references, it has evolved from niche professional instrument to one of the most quietly desirable sports watches in the Rolex catalog. If you're trying to figure out which one is yours — here's the complete breakdown.

Where the Explorer II Sits in the Rolex Lineup

The Rolex Explorer II often gets confused with two siblings. Versus the Explorer I: that's a cleaner, simpler watch — no GMT hand, no 24-hour scale. Versus the GMT-Master II: the GMT rotates its bezel to track a second time zone; the Explorer II's bezel is fixed, so the 24-hour hand tells you day or night at a glance, not what time it is in Tokyo. Same family, different purpose.

Explorer II Reference by Reference

Ref. 1655 (1971–1985)

The original. What makes it immediately recognizable is the bold orange 24-hour hand — a visual signature that's stayed with the line ever since. The market nicknamed it "Steve McQueen," though McQueen never publicly wore one. Don't let that bother you: it's a genuinely great watch regardless of the myth. Case: 39mm. Lug width: 20mm. Secondary market Rolex prices have increased significantly on vintage demand — verify current figures on Chrono24 before buying.

Ref. 16550 (1985–1989)

The rarest of the five references. Shortest production run, first to offer both white and black dials, and the reference that introduced sapphire crystal to the Explorer II line. It marks a genuine turning point in the model's history. Case grew to 40mm, lug width stayed at 20mm. Short supply and collector interest push secondary prices high — a very interesting investment timepiece, but worth verifying on Bob's Watches before you commit to purchase.

Ref. 16570 (1989–2011)

Twenty-two years in production, the longest run of any Explorer II and the direct predecessor to the 216570. Rolex refined it progressively throughout its run; the most useful identifier is the rehaut engraving that appeared post-2007. Case: 40mm. Lug width: 20mm. Secondary prices vary considerably by production year and condition. It's also the reference with the widest availability on the grey market. 

Ref. 216570 (2011–2021)

This reference is where everything changed. Case jumped to 42mm, crown guards got more pronounced, and — critically — lug width moved from 20mm to 21mm (most Rolex sports models sit at 20mm, which made this an unusual move). If you're buying used, this is the reference where aftermarket strap compatibility narrows. Secondary market pricing has been rising steadily as it moves further out of production.

Ref. 226570 (2021–Present)

The current Rolex Explorer 2 226570. Rolex refined the proportions of the 216570 for better visual balance and introduced Caliber 3285 — Chronergy escapement, 70-hour power reserve, significantly improved accuracy. The lug width changed again with this generation, this time to 22mm. For retail pricing and AD availability, check Rolex.com directly.

Verify all prices on Chrono24 and Bob's Watches before purchasing.

Why the Lug Width Changed from 20mm to 21mm in 2011

When the case grew to 42mm on the 216570, a 20mm lug looked visually wrong — too narrow for the case. Rolex moved to 21mm to restore proportion, and that single decision reshaped the aftermarket entirely.

The practical implication: vintage refs (1655 through 16570) run on 20mm straps, giving you access to virtually every aftermarket option available. Since 20mm is the most common size across sports watches. The 216570 needs 21mm and the 226570 needs 22mm, both with curved ends shaped specifically for the Explorer II case. That means you need an aftermarket strap built for the Explorer II. A smaller pool than 20mm, but the quality options are there. If you bought pre-owned without the original papers, the reference number is engraved on the case between the lugs at 12 o'clock, and the serial sits on the rehaut on post-2007 examples.

Polar Dial vs Black Dial

This is the question that splits the community. The Rolex Explorer 2 white dial (Polar) reads better at a distance and has historically traded at a 10–15% premium over the black on the secondary market — verify current spread on Chrono24. The Rolex Explorer 2 black dial is more discreet, better for daily wear if you're not looking to announce the watch.

One detail worth knowing: early 1655 dials develop natural tritium patina over decades — that aged cream tone has created its own micro-market inside the vintage world. On strap pairing, the pattern is consistent: Polar pairs cleanly with dark contrast straps (black rubber, dark navy), while Black works well either with tonal match or a strong chromatic accent like orange — a nod to that original 24-hour hand.

How the 24-Hour GMT Function Works

The Rolex Explorer 2 GMT hand completes one rotation every 24 hours. The fixed bezel is marked 1–24. Together, they tell you instantly whether it's AM or PM — useful underground, in polar regions, or anywhere light conditions are unreliable. This is not a dual time zone tool the way the GMT-Master II is. That watch has a rotating bezel to independently set a second city's time. The Explorer II's bezel doesn't rotate — it's calibrated for day/night orientation, not timezone math.

The Explorer II on the Wrist

What consistently surprises first-time Rolex Explorer 2 rubber strap converts is the weight. The Oyster bracelet on a 216570 or 226570 runs around 160 grams. A quality FKM rubber strap brings that down to roughly 35 grams. The watch feels completely different — more wearable, fresher to wear during hot temperatures  and less of a statement.

Polar dial owners make the switch to rubber more often than Black dial owners. The contrast between the white dial and a dark rubber strap has become the signature look for the modern Explorer II. Vintage ref owners (16570 and earlier) tend to preserve the original bracelet and use rubber selectively for travel. In summer, an orange strap picks up the orange details on the Polar dial nicely.

One technical note: the crown guards on the Explorer II are specific to this case — curved-end straps are not interchangeable with Submariner or GMT-Master II fitments. You need a mold made specifically for this case.

Fitting a Rubber Strap on the Explorer II

Vintage references (1655 through 16570) take 20mm FKM vulcanized with a curved end. The 216570 takes 21mm, and the 226570 takes 22mm, both with a curved end and an Explorer II-specific mold.

On color: Polar dials take almost any tone well — high contrast options work best. Black dials pair most cleanly with matte black or strong chromatic accents. The original Oysterlock deployant clasp mounts directly onto quality aftermarket rubber, so you keep the factory closure. No modifications, full reversibility. Fitting an aftermarket rubber strap does not void your Rolex warranty, provided the original bracelet is preserved and the watch itself is unmodified. Keeping the original bracelet untouched also protects resale value when the time comes to sell.