Hi,
A couple of years ago I bought this NRV from you-https://www.securitycameraking.com/product/elite-16-ch-4k-poe-nvr/
I had to downgrade the NVR's operating system so I could run some of my old cameras. Now I want to upgrade to Version 4.0.
Can you provide me with a safe link?
Regards,
Tubac