by Ed Delgado
The original bracelet on the 16520 from 1988-89 was a 78360 with a non fliplock clasp. The center links were not polished.
The second is a 78390 with center polished links.
The third bracelets were 78390A with a flip lock clasp but no divers extension was present.
In 1999 (A and P Serial) a new SEL (Solid End Link) bracelet was introduced. This eliminated the Rolex "rattle" of the bracelet.
For comparison, Below is a photo of a A Serial and R Serial Watches..