Hello, Piyapat-san.
I have thought that we have already replied you. But I am reporting it again.
The supplier take note the serial number from the beginning of
trial of this model.
Please check the attached file
P1 : serial number control table ( since Dec 2014)
P2 : Quality inspection status sheet of sub contractor for graving
P3 : Moving slip of the work
Although the supplier investigated on serial № 45901173,
there was no record that this number is duplicated.
If you have any question about this, please contact me again.