How do I find the machine serial number?

UV-curable Inkjet Printer - On the left side of the machine back.

 
   
Cutting Plotter - On the bottom of the machine.
   
   
Laser Engraver System- On the right side of the machine back.
 
   
Laser Marking System -
 
   
ID Card Printer
 
   
Thermal Printer - On the left side of the machine back.