In the year 2000, Rolex made a significant stride in horology with the introduction of their in-house movement, the renowned Calibre 4130, which was incorporated into the prestigious 116520 series Daytonas. What sets this particular timepiece apart is its distinctive dial, affectionately referred to by collectors as the 'APH' dial. This moniker originates from the noticeable spacing in the word 'COSMOGRAPH,' specifically between the letters 'R' and 'A.' These unique dials made their appearance during the final four years of the 116520's production. Notably, this example is in outstanding condition and features blue Chromalight luminescence on the hour markers and hands, ensuring excellent readability in low-light conditions.