The Brinno PHV133012 Digital PeepHole Viewer (12 mm Barrel) includes a brightness enhancement to help you see who is at your door when it's dark outside and an SD card slot (supports up to 32 GB) for saving a picture of the visitor every time you turn on the peephole. It comes with a 3" LCD screen so you won't have to squint to see who is at your door or let them know that you are home (no shadow is cast when you are viewing the PHV133012 display). What's more is that children can also view who's at the door without having to struggle to reach the peephole. Additionally, it features a zoom option to view the visitor more carefully and takes a picture of your visitor in the zoom mode too.
The Digital PeepHole viewer comes with the option to add accessories - a knocking sensor or a motion sensor. The knocking sensor detects the vibration of someone knocking on your door and sends a signal to the peephole, which in turn takes a picture of the visitor. The pictures are saved on an SD card, so once you reach home, you still get to see who visited you while you were out. The same goes for the optional motion sensor - you place a small motion detector outside your front door and when it senses movement, a signal is sent to the peephole to snap a picture.