Chuck's Watch refers to the chronometer Chuck wears in the early seasons of the show. It is revealed to have been designed by Laszlo Mahnovski.
Among its known features are a built-in tracking device and two-way radio/listening device. Chuck's first watch was destroyed by Laszlo to keep Sarah and Casey from tracking them. In several episodes he has deliberately left it behind when he doesn't wish to be tracked. The watch also either has an integral distress beacon, or, by "Chuck Versus the Best Friend", was upgraded to allow Chuck to turn the tracking device on and off.
Similar watches are also worn by Sarah and Casey. The watch is one of many devices used by the team that reference the gadgets of James Bond. In Chuck's particular case, however, the reduced emphasis on the watch appears to mark his own evolution as a spy.
Watch 1 - Chuck receives his first watch from Sarah in "Chuck Versus the Tango". This watch lasts until "Chuck Versus the Sandworm" when it is destroyed by Laszlo.
Watch (unknown number) - This watch was destroyed by the Italian mob members Chuck works with whilst posing as Rafe Gruber. They destroy the watch by crushing it into the ground, replacing it with an ordinary gold-plated watch. However, it is then later replaced.