It works normally, but there is a constantly annoying noise in the intercom (a zzzzzzzzzzz continuously)

It is a good solution if you don't have many cables available, it does a good job. The only peculiar thing is the red backlight on the name label, which might alienate some people.

Very good. Installed in a detached house. Cable distance is about 25 meters. Clear speech sound, loud ringing, it has the power supply inside the base of the headset and I connected it directly to the wall, covering the cables, so it looks like a professional installation. The external unit requires drilling into the wall to be installed at a depth of about 5-6 inches, it has orange-red lighting at the name entry point and overall it looks nice and functions perfectly so far.