They are Lilin cameras (OEM for Elan). They are ONVIF, nothing special. They will work with most recorders. The recorder will be kinda useless without the Elan controller and the app on their devices.

You can also do what we did on a job. We used Elan cameras and NVRs and set up the Elan app to be used as the surveillance recording interface. And then we just brought in the streams from the cameras to C4 for live viewing. We were hoping to eventually switch the rest of the system to Elan at some point, but he is hanging on to C4 because he has is at all his other houses.

I sent you a PM as well.