In Device Settings you have several options: Forget, Calibrate Now, Default Colorimeter Slider, and Connect/Disconnect
Forget - Click "Forget" to remove the Colorimeter from the known devices list in the App. A connected Colorimeter will be automatically disconnected if you choose this option.
Calibrate now - Calibrate the Colorimeter using the removable calibration cap. This will prompt the Calibration screen to open.
Default colorimeter slider - Use this to set the current Colorimeter as your default Colorimeter. The App will automatically choose this device if there are several Colorimeters in the vicinity.
Connect / Disconnect button - Disconnect the device if connected, search and connect to the device if not connected.