The serial number of the camera is available on a printed label under the box.
You can retrieve the serial numbers of all the cameras connected to a host device by using the launch option --all of the ZED Explorer tool.
Linux:
ZED_Explorer --all
Windows:
"ZED Explorer.exe" --all
An example of two cameras connected to a Ubuntu PC:
$ ZED_Explorer --all
## Cam 0 ##
Model : "ZED 2i"
S/N : 3*******
State : "Camera Available"
Path : /dev/video2
ID : 0
Type : "USB"
********************
## Cam 1 ##
Model : "ZED 2"
S/N : 2*******
State : "Camera Available"
Path : /dev/video4
ID : 1
Type : "USB"
********************