ROLEX, DAYTONA 'INVERTED 6', REF. 16520A STAINLESS STEEL CHRONOGRAPH BRACELET WATCH, NO. S729513, CIRCA 1993Movement: Cal. 4030, automatic chronograph, 31 jewelsCase: Stainless steel case, screw down crown and pushers, screw down case backDial: WhiteBracelet: Rolex Oyster stainless steel bracelet with fold over claspSize: 38mm, bracelet 19.5cmSigned: Case, dial, movement, crown, claspAccessories: Rolex box, guarantee certificate, swing tag, outer card packagingThe Daytona is one of the most sought after models in the Rolex line-up of watches. This was not always the case, as when it was initially released in 1963, sales were disappointing. This was to change however with the release of the reference 16520. Originally the Daytona was powered by a manual wind chronograph movement, but this new model came with an automatic chronograph. The reference 16520 was equipped with the calibre 4030, the first Rolex automatic chronograph movement. This is based on the Zenith El Primero movement, which Rolex replaced 60% of the parts. The 16520 was in production from 1988 until 2000, when Rolex introduced its own in house movement, the calibre 4130. This has made the 16520 sought after among collectors.The example being offered here is even more sought after due to a small detail on the dial. The number six to the hours sub dial is inverted and looks like a number nine. The dial went through a number of slight changes over the years, and each is known as a Mark. This example has a MKIII dial and comes complete with all its boxes and papers.