Bad choice, problematic operation, rude and useless service. Expensive and a failure this purchase.

DO NOT BUY IT!! The image is terrible, the microphone is terrible, the buttons, the speaker, all of it is a waste of money, it's not worth it at all. I connected it and it didn't work, the door wouldn't open and it almost burned us. It only worked for image and sound, and even those were terrible. Don't buy it, anyone!!

Very good product, I connected it to two apartments with utp cat6 at a distance of about 30 m. It also works wonderfully and the receiver that receives the command to unlock the door. Attention: Due to the metal casing, the external unit had a strong echo, and the internal unit had no sound on the external unit. The problem was simply solved by enlarging the microphone hole!
Update 1.5 years later: One of the two monitors has stopped working (it seems like the screen is overexposed with zero settings). It is not covered by the warranty (one year) and I have been looking for a monitor for two months. Nowhere to be found! So the after-sales service is a bit problematic.