From IMDB we have the following trivia:
"The film had various problems with designer labels during production. Cerruti agreed to allow Christian Bale
to wear their clothes, but not when the character was killing anyone;
Rolex agreed that anyone in the film could wear their watches except
Bateman (hence the famous line from the book "Don't touch the Rolex" had
to be changed to "Don't touch the watch"); Perry Ellis provided
underwear at the last minute after Calvin Klein pulled out of the
project; Comme des Garçons refused to allow one of their overnight bags
to be used to carry a corpse, so Jean Paul Gaultier was used instead."
It may be a Rolex copycat?
Cheers,
Nilo
Note: Bateman is Christian Bale's character.