Ring Alarm Contact Sensor (2nd Gen) - 2 Pack

Please note, to use the Ring Alarm Contact Sensor you'll need to download the free Ring app, which is compatible with all iOS and Android devices. You'll also need the Ring Alarm Security Kit (sold separately).Get alerts straight to your smartphone any time a door or window is opened with the Ring Alarm Contact Sensor 2-pack. Installation is simple - no need to call out an electrician - just stick some batteries in and use the self-adhesive pads to place them on your door or window frame. Also, the two halves of the sensor can be placed up to a maximum distance of 1.27cm away from each other, meaning they'll still work if you have a bit of gap between the door and the frame. And not only are they compatible with Amazon Alexa, but they'll work even if the WiFi is out thanks to Z-Wave wireless tech.