This is an accessory kit that includes a plug-in Wi-Fi Bridge and magnetic door sensors that need to be installed in the door.
The Wi-Fi Bridge allows you to connect your Freestyle Trilock to your home’s Wi-Fi network so you can access your lock remotely, receive alerts on who has accessed the house, etc. The Door Sensor allows you to view the status of your door. So, if you have locked the door remotely but left your door ajar, you will see this in your app.