iON Digital Micra Wireless Window Security Sensor, 2GIG (Micra-2GIG)

Great hidden little sensors. I would have given this five stars, except this is my third mysterious replacement of random sensors for a random reason. When they are working, they are great. (I have a few dozen of them.)

Description doesn't say that you need to drill holes into windows. Need a handyman.

Very easy to install. Website has very informative videos on installation.Printing on the antennae label could have been a bit clearer but the 2gig unit can learn to recognize this sensor automatically. I make a point to right down the sensor id info in case I ever have to reset my system.