Increasingly collectable 'R-series Rail Dial' Explorer II - The very first of these 16550 sapphire glass models feature some of the most distinctive dials ever to leave the factory. Its white 'rail dial' nickname stems from the text configuration used by the Stern Company, (manufacturers of the famous Comex dials) whereby the space inbetween "Superlative Chronometer" & "Officially Certified' align to create a vertical track or "rail". The lume on this example, with correct white gold surrounds, has aged to a gorgeous cream colour which really pops against the white dial perfectly. We almost never get to see these as complete sets so to have one with original 'green stripe' box, punched papers, cave Explorer & Oyster booklet is a rare treat.