On the inside of the clasp hinge is a code that designates the month and year that the clasp/bracelet was manufactured. When examing watches at an AD or watch mart, do not be surprised if a bracelet is a few years older than the watch case. In modern Rolex watches, it is rare to find a clasp code that is the same year as the watch case.
On the clasp hinge is one or two letters followed by a number. The letters represent the year code, and the numbers signify the month. A clasp code of OP9 indicates the clasp/bracelet was manufactured in 2006, and the number indicates the month of September.
* (e.g. CX3, J4M, 5AM, etc)
S = Service: Clasp replaced during a “S”ervice.