TEKMAGIC W70 Mode D'emploi page 8

5.8 Press the MODE button once to exit the stopwatch mode.
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Notes
1. The stopwatch timing range is 0:00'00'' to 23:59'59".
2. If you don't stop the timing, the stopwatch will continue to timing and start timing from 0:0'00''
even the timing is over 24 hours and you have exited the stopwatch mode.
VI. Back Light
Press the LIGHT button to turn on the electro luminescent backlight. The backlight will be turned off
automatically in about 3 seconds.