Rolex ref 6098 Explorer
Rolex Explorer ref 6098.
This is the very first professional watch who gave birth, with the 6298, to the Explorer mith.
As the very first it don't bear the Explorer name on the dial.
The case is a 36mm size, big bubbleback shaped, in s.steel.
The caliber is the Automatic A296.
This example is from 1957.