Rolex Explorer I watch, round stainless steel case (39mm diameter, 11mm thickness), polished stainless steel bezel, stainless steel Oysterlock bracelet, black dial with silver/luminous Arabic numerals and luminous index hour markers, 31 jewel Caliber 3130 self-winding Oyster Perpetual certified chronometer movement, scratch-resistant sapphire crystal, water-resistant to 100 meters.