What does “AM” mean?

AM is short for aftermarket: a part that was not made by the watch's brand, or that was added after the watch left the factory. In watch listings it most often refers to aftermarket diamonds, bezels, dials, straps, bracelets or crowns, and sellers use it in shorthand such as “AM bezel” or “AM diamonds”.

Aftermarket parts usually reduce the value of a watch to collectors and to dealers who buy for resale, because most buyers want watches as the brand made them. They can also affect servicing, as brand service centres may refuse to work on modified watches or may insist on replacing the non-original parts. That is why honest listings disclose every aftermarket part clearly, and why buyers check photos closely for signs such as uneven gem setting, mismatched lume or markings that do not fit the reference.

Typical usage: “Datejust 36, steel, AM diamond bezel and AM dial, original bracelet, priced accordingly.” The opposite of AM is OEM or genuine.