2 Answers

First, there are a variety of other Rolex models that also say Explorer on the dial link – these are most typically from the early 1950s, when Rolex seemingly had not settled on exactly what the link Explorer I would be. There are also other models (like the link obscure Explorer Date reference 5700 from the 1960s) worth a mention, but which don't follow the standard design cues of the Explorer I.

The Chronoking just like all of its other Mecaquartz versions comes in at 38mm in diameter link with a 13.4mm thickness. Inside link is a VK63 link Mecaquartz movement with a quartz timekeeping element and a mechanical module on top for the chronograph functions. A quirk of the mecaquartz movement the three o'clock subdial features a fixed 24-hour time indicator. The Chronoking Mecaquartz starts at 579 about 100 more than the standard variant surely on account of the five interchangeable bezels.