Functional, but slightly overpriced for a 'glorified walkie-talkie.' It does give great peace of mind as you don't have to open the front door to check who's behind it. The quality of the product is good and the sound quality between the occupier and visitor is excellent. I like the fact that it's wire-free too. My only two conerns are that the batteries might run out quite quickly, meaning you have to demount the device from the wall, unscrew the battery compartment and pay for new batteries once in a while. My second concern is that a feature of this product is a so-called 'alarm' to 'scare away intruders.' Please DO NOT expect this to do that. Why? The visitor can deactivate the alarm by holding the 'TALK' button on the outside unit. This actually silences the alarm which is VERY bad design. The alarm is extremely quiet and not the least bit startling. The intruder would probaly just laugh at it, take it off the wall and stamp on it. I would reccomend buying this as the ability to talk to visitors before opening the door is fantastic and well accomplished, though the additional alarm feature is just awful.