To send an alert, hold the recessed ring button for 3+ seconds. During your push   the ring will emit three short and one a long vibration and the LED will turn green after 2 red blinkings.

-  There is a variable timer countdown of up to 30 seconds before an alert is sent to provide the user with an opportunity to cancel an alert in the event it was activated by accident. You can open the Nimb app on your phone and cancel the alert manually before the timer countdown is complete. Or you can confirm the alert before the countdown is complete. Even after the countdown is complete and the alert has been sent, a user can cancel the alert using a pin code. 

-  Once an alert is confirmed as sent, the ring will emit a very long vibration with the green LED identification. No indication (both vibration and LED) means an alert can’t be sent. If this happens, the user needs to examine the app for the cause and to take steps to make the alert operational again.