Rolex Daytona ref.16520 NOS de 1997

The story begins in 1988 at Baselworld when Rolex unveiled the new incarnation and most significant redesign of its flagship sports watch, the automatic Daytona. The 16520 Daytona announced the introduction of a new 40mm case and a sapphire crystal. Previous 62xx Daytonas had plexiglass crystals, so the introduction of robust sapphire crystals in the new case meant Rolex could guarantee the watches to a depth of 100m (330ft). This was Rolex's first automatic-winding chronograph. Rolex's new Daytona was powered by a highly modified Zenith "El Primero" movement, the Calibre 400, which formed the basis of the new Rolex 4030 movement. Due to its very demanding standards, Rolex made more than 200 modifications to the base caliber. The movement had a power reserve of 52 hours and featured 31 jewels, a Breguet free-sprung balance spring, and most importantly, the automatic rotor. This movement served Rolex well for 12 years until Rolex launched its own in-house movement, the Calibre 4130, wh