Insteon Hidden Door Sensor - Door and window Product Details
Nothing makes your home smarter than adding sensors; but even the unobtrusive open/close sensor can be too large for certain décors and locations. That's why the Hidden Door Sensor was created. Instead of mounting to the surface of your door, Hidden Door Sensor is installed inside the door frame or even the door itself. The result is a completely hidden sensor that stays out of the way, monitoring doors without the slightest visual impediment.