How do I tell which system I have – Gen1 or Gen2/Gen2+/Gen3?

Our Gen1 systems are manufactured by Infomir in Ukraine.  Some models have a logo “MAG” in large letters on the top of the device…

This is a Gen1 system:

Other models have a red circle on the top of the device…

This is also a Gen1 system:

If you do not have one of the two above devices, then you have a Gen2, Gen2+, or Gen3 system.