Assembly Needle
Removes the fixation ring, which holds the jewelry discs. The pike of the needle is pushed from above into the notch and under the fixation ring to pull it over the rim of the watch casing.

Time Setting and Adjustment
To set the time on the Deja vu watch, the assembly needle is used to press the small button on the back of the watch casing. The minute hand moves with short individual pushes. Holding down the button causes the minute hand to move continually to the desired setting.