Module

Model: 1015471_E (for Men's watch) Diameter: 27 mm Thickness: 6 mm
Battery: LR754 Face: LCD 4 digit Light: TritiumYear: 1979 Buttons: Two buttons are used, top right and bottom right.
Function: It displays hours, minutes, seconds, and the day of the week. It is equipped with an integrated light of a particular type that was banned for use in Italy in the 80s, Tritium.
Info: This module is used in the following modelTI-551-02, TI-551-10, TI-552-10, TI-552-20

Here you can see the special contact the button uses when pressed. Two buttons are used: the one on the top right to display the date and seconds, and the one on the bottom right to set the time and date. This module was unique because it used a special type of illumination: tritium, which was illegal in Italy in the 1980s but widely used in the United States. Another special feature was the internal chip; in the last photo you can see how it was glued and electrically connected to the watch's PCB.