Upgrade your everyday peephole to a motion-detecting, two-way-talking, HD video doorbell. Easy to install and completely non-invasive, Peephole Cam sets up or comes down in minutes making it perfect for both homes and apartments. See who's at your door, sense knocks, and get alerts from anywhere, so you can spend less time worrying about home and more time enjoying your every day. Peephole Cam is compatible only with standard size peepholes 1/2in to 9/16in (12mm to 14mm) and door thickness ranging from approx. 1.3in to approx. 2.2in (34mm to 55mm).