Visonic Mct-340 SMA Wireless Door Window Sensor 2.4ghz for Xfinity -Very small, thin form factor able to blend into the decor of most installations -Easy installation using high-strength 3M mounting tape (included) -Wide Gap performance able to be installed in tough situations where magnet gap is over 1" -Battery level data routinely transmitted. Low battery condition also transmitted. -Tamper alert is reported when a tamper event occurs and in any subsequent message, until the tamper switch is restored.