Rolex, Explorer II, ref. 1655, a stainless steel bracelet watch, no. 3181543, circa 1972, automatic movement, 26 jewels, adjusted to 5 positions and temperature, black dial, luminous baton markers, white luminous pointed baton hands, centre seconds hand, orange centre 24 hour indicator arrow hand, date aperture at 3 o'clock, the bezel with Arabic numeral 24 hour index, screw down crown, screw down case back, on a Rolex stainless steel Oyster bracelet with fold over clasp, case back, dial, movement, crown and clasp signed, accompanied by a Rolex box, guarantee certificate, two spare links and outer card packaging, diameter 38mm, bracelet 20cm Introduced in the early 1970's, the Explorer II came with additional features over the Explorer I. A fourth hand was added for 24 hour indication, a 24 hour index to the bezel and a date window. It was basically a GMT-Master with a fixed 24 hour bezel. The Explorer II was targeted at speleologists (cave explorers) who could lose all track of time and sense of day or night.