This door/window sensor almost disappears on your door or window. Barley over 2″ long and only half an inch thick. Door and Window sensors are the building blocks of your security system. They help keep you safe while you’re in, and are sure to keep unwanted visitors out. With our door/window sensor you’re always connected to your home. Place these sensors on each door and window in the home to create a protective perimeter around your home. Know when these doors and windows are opened with customizable chimes and create unique names for each entry and know when they have been opened and closed. You can even receive messages to know when a door is left open with our interactive app! Not only can these sensors be put on doors and windows, but they can also detect the opening and closing of many other things…drawers, cabinets, etc.