How do I know if I have the Gen 1 or Gen 2?

My Cloud OS 3 Personal & Network Attached Storage My Cloud Mirror
1

Just purchased the MyCloud Mirror…how do I know if I have the Gen 1 or Gen 2?

2

Article number of My Cloud Mirror is

WDBZVM0040JWT (this is the 4 TB version),

Article number of My Cloud Mirror Gen.2 is

WDBWVZ0040JWT (again 4 TB version)

3

Hi There. I have a 3TB drive P/N WDBCTL0030HWT

Is it a gen1 or gen2

Thank you very much.