Easily keep track of garage doors, cabinets, or mail boxes. The Door Sensor Pro's magnet is only 1/4" wide, and can be placed up to an inch away from the sensor, letting you monitor previously impossible openings. The Door/Window Sensor Pro uses S0 encrypted communication, so you don't have to worry about unusually high-tech burglars breaking into your home. I mean, imagine if they used that talent to do good? It's a shame, really.