Man

Model: 1035758_8 rev. L (for Men's watch)
Battery: LR41 Face: LCD 6 digit + week Light: Yes Year: 1979 Buttons:  Two buttons are used, top right, bottom left (light)
Function: It displays hours, minutes, seconds, and the day of the week, and has a stopwatch with hundredths of a second. It does not have a built-in light.
Info: This module is used in the following model  TI-3553-11, TI-3553-21, TI-3553-31, TI-3553-41 

Here you can see the particular contact that is used by the button when pressed. Only two buttons are used, one on the top right and one on the bottom left (light). The top right button allows you to select the date and day of the week, while the bottom left button activates the micro-bulb for illumination. To set the settings, press both buttons simultaneously.