This superlative Day-Date delivered in 1986 bears the 18039 reference, which was released between 1977 and 1988. The fifth digit number of the reference - in this case 9 - indicates the metal of the watchcase: 18 carat white gold. The rare and gorgeous turquoise “Lacquered Stella” dial found in this Rolex Day-Date in white gold with sapphire crystal is further enriched with 8 round cut and 2 baguette-cut diamonds.Since 1977, Day-Date models beginning with reference 18000, are fitted with sapphire crystals, which replace the traditional Esalite glass (an elastic easy to polish plexiglass). In order to house this new glass, the bezel underwent a restyling. As a result, together with the screw-down case back and screw down crown, it is waterproof to 100 meters, which is equivalent to 330 feet.