ROLEX, REF. 1016, EXPLORER, A FINE AUTOMATIC STEEL WRISTWATCH WITH CENTER SECONDS CIRCA: 1970CASE MATERIAL: Steel CASE DIAMETER: 35mmSERIAL NO’: 2119887DIAL: Black    MOVEMENT: AutomaticBOX: NoPAPERS: NoThe celebrated Explorer reference 1016 was introduced to the market in 1959. One of Rolex's most popular sports watches, the Explorer is easily recognizable by its black dial with the luminous triangle at 12, luminous Arabic numerals for the other three quarters and luminous baton numerals for the remaining hours.