Rolex Explorer II 16570 White

The case measures 40mm across, with a 20mm lug width. Case material: Stainless steel. Case size alone is a poor guide to how a watch wears; lug-to-lug length and how the bracelet drops off the case matter more, which is why we suggest trying one on before you commit.

Automatic, Rolex Cal. 3185 (later 3186). Power reserve is 48 hours. It beats at 28,800 vph.

It is rated to 100 meters, about 328 feet. That is enough for swimming and snorkeling, but not for scuba diving. One caution that applies to every watch on this page: a water resistance figure describes a new watch with fresh gaskets. On a piece that is years past its last service, treat the rating as unknown until it has been pressure tested.

Rolex produced this reference from 1989 to 2011. Production years matter when you are valuing one, because dial, bezel and bracelet details often changed inside a single reference run.

165 = Explorer II case generation; 70 = steel; fixed 24-hour bezel, sapphire crystal. Reading the reference is the fastest way to confirm that a watch is what the seller says it is, before you get anywhere near the movement.

Explorer II 40mm -- white or black dial, aluminum 24-hour bezel. Collector nicknames are not official Rolex names, but they are what people actually search for and what they are called across a showroom.

Yes. We buy this reference outright, and we lend against it if you would rather keep it. We are a family-owned San Diego buyer established in 2006, our appraisers are GIA-trained, and the appraisal is complimentary with no obligation to sell. You can bring it to our Gaslamp showroom at 907 Sixth Ave or start online. If you are looking to buy this reference instead, tell us and we will let you know when one comes in.