Swann Security - WiFi Window/Door Sensor - 1 Pack Complete Peace of Mind - Always know what’s happening & be protected with this window or door alarm sensor to trigger mobile phone notifications & optional siren (sold separately). Easy to Use - If a door or window is opened, disrupting the magnetic connection between the Sensor & Receiver, you can activate/deactivate remotely using the app. Perfect for Renters - Do-it-yourself with ease. The sensor mounts with double-sided adhesive. No need to drill walls. Ideal for apartments & rental properties. More than an Alarm - Combine with an add-on Indoor Siren (sold separately) for audible alerts to know if there’s activity even if your phones not handy. Build Your Own Security - Connect on the Swann Security app & add additional Swann Wi-Fi sensors, siren, cameras & accessories to fit any home, apartment, or business for complete security. Depth: 46 MM Easy Install - Connect in minutes Mobile Alerts - Always stay in touch with push notifications when activity is detected No Hub Required - Cost-effective alerts Multi-Purpose Use - Perfect for doors, windows 2.4GHz Wi-Fi - Easy wireless operation Smartphone Control - Control using the app Batteries Powered - Batteries included (AAA x 2) Add a Siren for Audible Alerts - Add sensors, siren, cameras & more Height: 20 MM Width: 66 MM