I started researching smart doorbells after dealing with too many packages not being left by FedEx because they wouldn't knock on the door and I live in an upstairs unit. First I would like to address much of the unfair in my opinion negative comments regarding this product. The biggest one I have noticed was regarding power issues. Doorbell wiring comes in numerous sizes, and in numerous voltage, all depending on when it was installed and by who My house was built in the 1900’s and it was a nightmare trying to identify and follow the wiring. Most of it is not consistent across the board which makes building a product compatible difficult, additionally in some homes wiring in low voltage systems sometimes gets crossed as well. So before buying any doorbell system, research and make sure it will be compatible with your setup which includes doing your own due diligence and figuring out what you have for a setup.