Should you become unpaired, in most cases opening your app will automatically repair your Arc.
To check the status of your pairing and manually repair your Arc: Open your KATANA Safety App > Click the menu button (the three lines) in the top left of the screen > From the menu drop down, Select “My Devices” > Touch the Arc listed under My Devices to open > "Bluetooth on" and "Paired" should both have green check marks next to them.
If successful, click "Done" in the Top right corner and then "Home" from the menu drop down to return to the home screen.