International Crystal, of course.

Beware, however. These people are perfectionists and simply specifying
268.435 MHz isn't enough. The oscillation frequency depends on a number of
factors, and they will expect you to know all about the circuit you are
going to use the rock in.

Sounds like a mighty high frequency rock, though. If such a thing can be
made, don't expect it to be cheap.

...

"Mauro" wrote in message
...
I'm looking for a producer that can make 2 pieces of quartz at 268.435 MHz
(or 134.217MHz).
Any advice please?
Thanks.
Mauro