Some info la...
# Air King: Entry level Rolex, all steel only
# Explorer: Entry level professional series watch, certified chronometer, Arabic numbers and black dial only, originally created for first ascent of Mt. Everest
# Explorer II: 24 Hour Bezel, extra hand for dual time zone purposes, all steel only
# Oyster Perpetual: Non calendar basic certified chrono, Oyster bracelet only, in all steel, in steel and gold
# Oyster Perpetual Date: Calendar, certified chrono, Oyster bracelet only, in steel, in steel and gold, in all gold
# Oyster Perpetual Date just: More options in dial choices, Jubilee band available, fluted bezel available, in steel, in steel and gold, and in all gold
# Submariner: First diver's watch, pressure proof for 1000 ft., available in steel or without date also in two tone with date only and all gold
# Sea-Dweller: Pressure proof to 4,000 ft., the diver's watch, helium escape valve necessary for deep sea saturation diving, steel only
# Yatch Master: 1192, Similar in design to the submariner but dressier, steel and gold, all gold
# Daytona Cosmograph: Introduced in 1939, has chronograph function (Stopwatch) steel, steel and gold gold , worn by Paul Newman
# GMT-Master: Introduced in 1954, for use by airline pilots, equipped with a 24hr. rotating bezel and 24hr. hand enabling dual time ability, all steel
# GMT Master II: Introduced in 1983, 12 hour hand is independently adjustable for ease of dual time zone traveling, steel, steel and gold, all gold
# Thunderbird: Descendant of Submariner, rotating turn-o-graph bezel, dressier than Submariner, steel and gold
# Day Date President: Introduced in 1956, all gold, platinum, day of the week is spelled out in full, president bracelet
Lady Date just President: Same as datejust but with president bracelet, no day, calendar only, all gold